Code p0420 chevy equinox

Replied by Chad on topic Intermittent P0089, P228D 2011 Chevy Equinox 2.4 AWD. The fuel rail pressure sensor detects fuel pressure within the fuel rail. The engine control module (ECM) provides a 5 V reference voltage on the 5 V reference circuit and ground on the low reference circuit. The ECM receives a varying signal voltage on the …

22 thg 12, 2019 ... Check engine light came back on. Took the car to Chevy for a better diagnosis, three things came up, O2 sensor #2 so replaced it again, spark ...P0420 is probably the most common code seen. It refers to "Catalytic Converter Efficiency" Basically, it Engine Control Module (ECU) monitors the …Code p0014 and P0420, I just bought this car previous owner said needed oil change and tune up, 2011 Chevrolet equinox, - Answered by a verified Chevy Mechanic. ... I have a 2011 chevy equinox with the 2.4l. I have codes p0420, p0455, p0013. I know what these codes mean, the problem i'm having is I can't clear them out. ...Re: 08 Equinox Sport P0420 code NIGHTMARE Where did you purchase this car - a Chevy dealer, another dealer, or a generic used car lot ? 2018 Equinox LT1 1.5 L 4 cyl, AWD, S/R Cajun Red Tintcoat/Black 2010 Equinox LTZ 2.4 L 4 cyl, FWD, S/R Cardinal Red/BlackThe best years of the Chevrolet Equinox are 2019-2021, 2016-2017, and 2012-2015. The years you should absolutely avoid are 2005-2007, 2008-2011, and 2018. Most issues are related to engine problems, but there’s also a chance of transmission failure on a few models, as well as brake or AC/heater trouble. Brian Jones.

Common Reason: Code P0420 is often related to a bad catalytic converter. P0420 means the catalytic converter is not efficiently removing pollutants from the exhaust. Your car won’t pass an emissions test. A bad catalytic converter isn’t a hazard to the driver but it can overheat and destroy engine components.P0172 is a diagnostic trouble code (DTC) which indicates that the fuel-to-air ratio in the Chevy Equinox is too high. This code is most often caused by a vacuum leak, an incorrect fuel pressure, an exhaust leak, or a faulty fuel injector. Short-Term Effects; The most common short-term effects of a P0172 code in the Chevy Equinox are decreased ...FFV 6-speed Automatic. Check engine code p0420 bank #1 - 2012 Chevrolet Equinox LS 4dr SUV 2.4L 4-cyl. FFV 6-speed Automatic. Posted by Anonymous on Jan 05, 2014. Leaded fuel was used where unleaded was called for. An oxygen sensor is not reading (functioning) properly. The engine coolant temperature sensor is not working …P0138 is a common OBDII code that occurs in many vehicles, including the Chevy Equinox. The code is triggered when: The voltage at the sensor remains above threshold for 20 seconds or more. Voltage to the sensor is to high (wiring problem, think short) Bad O2 sensor itself. There are also some less likely problems that can cause P0138.I changed the o2 sensors 2008 Chevy Avalanche. Check engine light comes up every 2 weeks. sometimes a bit of rough idle at 500 RPM other times runs great. ... I have a p0420 code on my 2018 chev equinox lt 1.5 tubrocharge. But mechanic saying it might be my o2 senor but I change and code still come up. Should I just change …P0420 code for 2012 Chevy equinox 2.4 flex fuel. No. No noticeable change in fuel consumption it does sometimes cut off after starting for the first time in the morning it also gets a rough bumping when you come to a stop after driving for awhile ...If your Chevy Equinox has the P0420 code, it means that the catalytic converter is not functioning properly. There are a few things that can cause this, but the most common …

Get ratings and reviews for the top 12 foundation companies in Chevy Chase, MD. Helping you find the best foundation companies for the job. Expert Advice On Improving Your Home All Projects Featured Content Media Find a Pro About Please ent...Popular Engine Codes P0420 P0172 P0171 P0128 P0300 P0456 P0430 P0442 P0455 P0113. Or check out our Diagnostic Trouble Codes Directory if you don’t see your code in the list of popular codes above. The Chevy Silverado & Other Chevy Check Engine Lights. If you’ve got a Silverado, check out our article on the best and worst years …I have a 2012 Chevy Equinox with codes PO300, ... Need help on a 2011 Chevy equinox LT, has a code of: P0420. Hi, need help on a 2011 Chevy equinox LT, has a code of: P0420. If i clear it out , It comes back before starting the car again. Bad O2 Sensor? Thanks in advance, ...From the 2014 GM Repair Manual for both 4cyl and V-6: Start and idle engine for 3 minutes, high idle will start to decrease to normal. Ignition off for 60 seconds. Start and idle engine for 3 minutes, Drive and watch for normal idle, repeat procedure if necessary, clear all codes.Common Reason: Code P0420 is often related to a bad catalytic converter. P0420 means the catalytic converter is not efficiently removing pollutants from the exhaust. Your car won’t pass an emissions test. A bad catalytic converter isn’t a hazard to the driver but it can overheat and destroy engine components.You may ever experience troubleshooting, such as P0420 Chevy equinox. It happens after your car is connected to the scanner. The code appears to indicate there is an issue related to catalyst system efficiency. Based on this result, it seems your issue comes from the catalytic converter. It is capable to scrub pollution, so the emission is free ...

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The first step is to check the engine light to see if the P0420 code is illuminated. If the engine light is on, then the next step is to check for any other codes that may be accompanying the P0420 code. Once any other codes have been addressed, the next step is to inspect the exhaust system for any leaks or blockages.About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright ...P0010 is a relatively common trouble code. It affects vehicles with variable valve timing (VVT). The list of VVT vehicles is growing, and the Chevy Equinox can have VVT and is prone to developing this code. P0010 is often by low or sludgy oil. Check your Equinox's oil as soon as possible. P0010 is a.El código Chevrolet DTC P0420 se activa cuando el sensor de oxígeno delantero (banda 1) situado antes del catalizador y el sensor de oxígeno trasero (banda 2) detectan una anomalía. Si los gases detectados por ambos sensores son parecidos, querrá decir que el catalizador no está cumpliendo su función. Por tanto, el sistema enviará este ...Nov 27, 2017 · The code P0420 for your 2.4 L engine is for the after the catalyst O2 sensor. Your vehicle has only two O2 sensors. One is in manifold before the catalyst and the other is after the catalyst. The code can be from a defective sensor or catalytic convertor. The system should have further tests done to make sure the correct part is replaced before ...

Jun 4, 2018 · P0420 code will clear itself if after several drive cycles the computer sees O2 S2 creating a voltage consistently above 0.5v and only going below that during a throttle closed "coasting". Under load (driving down the highway, climbing a hill, acceleration) the voltage of O2 S2 should be consistently high and not drop below 0.5. Chevy Equinox P0013: “B” Camshaft Position → Open/Short OCV → Bank 1. P0013 is a somewhat frequent OBDII trouble code. It is generic, which means that it has the same meaning for the Chevy Equinox, as it would any other vehicle. It only affects vehicles with Variable Valve Timing.P0420 - 2010 Chevy Equinox LTZ 6CY - O2 BANK LOCATIONS. I am getting a P0420 - Catalyst System Efficiency Below Threshold (Bank 1). The 2010 6CY has two converters that come off the engine. One on the back of the engine towards the rear of the car and one on the front of the engine that comes off the front of the car.P0324 is a diagnostic trouble code (DTC) for "Knock Control System Error". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $154.99 .Nov 27, 2017 · The code P0420 for your 2.4 L engine is for the after the catalyst O2 sensor. Your vehicle has only two O2 sensors. One is in manifold before the catalyst and the other is after the catalyst. The code can be from a defective sensor or catalytic convertor. The system should have further tests done to make sure the correct part is replaced before ... Mar 26, 2019 · Conclusion. P0506 is a serious issue. Due to the unsafe nature of driving with an engine that can stall at any time, we recommend having your Equinox serviced as soon as possible. Good luck! P0506 is a common OBDII trouble code. It is typically triggered when the engine idle speed is lower than the predetermined limit set by the manufacturer ... Mar 23, 2021 · Have you run a scan of all 4 code families to see if any are present outside of just the P codes? Malibu and Equinox forum contributor '20 High Country Silver Ice Met.-'16 Equinox 3.6 AWD LTZ -'23 Silverado 6.2 LTZ-Ski Doo's-FLHR-F3S Spyder-Boats Service Procedure Equinox, Terrain Important: For the 2.0L engine ONLY, remove the boost sensor from the intake charge pipe to the throttle body and wipe with a clean rag to remove residual moisture. 1. Perform a smoke leak test of the charge air cooler. 4597334 • If a leak is determined, replace the charge air cooler with the newly designed ...What Does Chevrolet Equinox Code P0300 Mean? Chevrolet Equinox P0300 definition: Random, Multiple Misfire Detected Issue Severity: SEVERE – Stop driving immediately Repair Urgency: Fix this code immediately (same-day if possible) to avoid ignition failure, catalytic converter damage, and dangerous conditions Diagnosis: A …Results 1 - 17 of 17 ... 4L O2 sensors">Q: code P0420 on my 2012 Chevy Equinox 2. The average cost for a Chevrolet Equinox Oxygen Sensor Replacement is between $232 ...

The P228D code triggers when the powertrain control module detects the actual fuel rail pressure is higher than the desired pressure. Note: The definition of the P228D code can be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

SOURCE: engine code p0420 on 2002 Chevrolet Express Van V8. Hello! the code you speak of relates strictly to the catalytic converter. it is possible there is a faulty sensor, however that choice is highly unlikely.Replied by Tyler on topic Chevrolet Equinox Set A Code p228D and p0089 Reduced Engine Power I like pole71's suggestion to investigate the rail pressure sensor. A quick check is to run the low …P0172 is thrown when the oxygen sensors detect that the air-fuel mixture is too rich. A rich fuel mixture contains too much fuel in relation to air. The A/F ratio for ideal combustion is 14.7 parts air to 1 part fuel (14.7:1). With that in mind, either too much fuel or not enough air can cause a vehicle to run rich.P0191 Chevy Equinox code meaning. If you’re a Chevy Equinox owner and have been getting the P0191 code, don’t worry, you’re not alone. The P0191 Chevy Equinox OBD-II code is a common one and usually indicates a fuel rail pressure sensor issue.. In this post, we’ll go over what the P0191 code means, what causes it, and how to fix it.Aug 10, 2018 · When there is a large leak in the Chevy Equinox’s EVAP system, it will throw the P0455 OBDII Code. P0455 indicates a large leak in the evaporative emission control system. (EVAP). There are different leak size codes. For example, P0456 means your Equinox has a small EVAP leak. While the trouble code may state that there is a “large leak ... This page is meant to help you troubleshoot the Chevy Express P0430 trouble code. It covers the P0430 code's meaning, symptoms, causes, and possible solutions. P0430 is an emissions-related trouble code and is virtually never a breakdown risk. P0430 is usually caused by a catalytic converter issue or a bad O2 sensor. Table of ContentsI have Chevrolet Impala 2014 model. Recently my car showing dtc code 0420. I read a article here . ... Check Engine code P0420 Catalyst efficiency below threshold bank 1. 3. Starter Turns Over then Engine Stalls. 7. 2003 Toyota Corolla, 185k: erratic OBD codes, fuel smell, other symptoms. 7. my 2011 Chevy Equinox check engine light on, …P0420 is one of the top 5 trouble codes for the Chevrolet Equinox. Chevrolet Equinox P0420 Symptoms. Check Engine Light is on; Lack of power from the engine; Decreased fuel economy; Rotten egg or a sulfur smell; How Do I Fix Chevrolet Equinox Code P0420? The first step is to get it diagnosed to figure out what is causing the catalytic converter ...

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If the efficiency is lower than it should be, the ECU will store OBD-II code P0420. The definition of the OBD-II P0420 code is “ Catalyst System Efficiency Below Threshold (Bank 1) ”. When the ECU stores this code, it means that the catalytic converter is not operating at maximum efficiency and may need replacement. Car fault code: P0420.Sep 13, 2023 · What Does the P0420 Code Mean? Diagnostic trouble code (DTC) P0420 stands for “P0420 Catalyst System Efficiency Below Threshold (Bank 1).”. It indicates that the exhaust system’s oxygen levels are below the required threshold in Bank 1, which can damage the engine’s exhaust and fuel system. One of the most misdiagnosed check engine lights is EVAP codes. Most people feel a new gas cap will fix the light. In some cases, they are correct! if you ar...If your Chevy Equinox is displaying the code P0420, it means that the catalytic converter on your vehicle is not functioning properly. The catalytic converter is a key component of your vehicle’s emissions system, and when it’s not working correctly, it can cause increased pollution and damage to your engine. The Diagnostic Trouble Code (DTC) P0420 in a 2006 Chevrolet Equinox indicates a potential issue with the efficiency of the catalytic converter in the exhaust system. This code points to the Bank 1 catalytic converter not performing its job of reducing emissions as effectively as it should. The P0420 code can be caused by several factors, …The P0420 code signals a low catalyst system efficiency. This code suggests that the oxygen levels are below the desired threshold (Bank 1), which most often results from problems with your car ...See Part_2 for loose timing chain. https://youtu.be/Xa09SV8tprQFor Buick Regal 2012-2013, 2015-2017For Buick Verano 2012-2017For Chevrolet Captiva Sport 2012...Feb 23, 2022. #1. Wife's 2013 Equinox 2.4 has had a recurring P0411 secondary air injection low flow code for about a year. Googling turns up that this is yet another delightful feature of the Ecotec 2.4, with a variety of causes. So far I've determined the electric air pump runs, because I can hear it. The condensation and ice that are …Possible Solutions: Avoiding P0420 Code Issues: Diagnostic Guide to Troubleshoot the P0420 Code on Chevy Equinox Advanced Diagnosis to Resolve the P0420 Code – …D. dell30rb Discussion starter · Apr 2, 2018. 2011 Equinox 2.4L is throwing code P0420 repeatedly. Runs fine and no other codes. New o2 sensors. Has 185,000 miles on it and now on engine #3 so its time to replace. Those engines have burned a lot of oil as we all know and i'm sure the cat is coked up with junk. ….

Service stabilitrak, flashing CEL and rough idle. After a week of not being driven, finally threw codes P0302 (cylinder 2 misfire) and P0036 (downstream o2 sensor). The shop says it looks like someone tried to steal my catalytic converters and cut o2 sensor wire.Would a downstream sensor cause (specific cylinder) misfire, and sudden rough idle.Code P0446 sometimes indicates that an electrical failure has been detected in either the vent valve itself or its control circuit. While the P0446 can indicate an electrical problem on later model Fords, which, for some strange reason chooses to look at the vent valve electrical circuit to set this code, the P0446 code is highly unlikely to be ...P0411. I have a 2013 Chevy Equinox 4 cylinders LT, I bought it a while ago. I bought it even though it had the check engine light on, it I didn't care about it. Then, I realized that if the check engine was on it wouldn't remote start. I checked the code and it was a p0411 By definition, the code is letting you know that the ECM has detected ...Are you in the market for a new car and interested in leasing a Chevy Equinox? Leasing can be a great option for those who want to enjoy the benefits of driving a brand-new vehicle without committing to long-term ownership.FFV 6-speed Automatic. Check engine code p0420 bank #1 - 2012 Chevrolet Equinox LS 4dr SUV 2.4L 4-cyl. FFV 6-speed Automatic. Posted by Anonymous on Jan 05, 2014. Leaded fuel was used where unleaded was called for. An oxygen sensor is not reading (functioning) properly. The engine coolant temperature sensor is not working …Emissions Codes P0420 and P0430: Catalytic Converters. Author: Max. Updated date: Sep 1, 2023 8:12 PM EDT. Catalytic converter. Kim2480 via Wikimedia Commons (CC BY-SA 3.0) Check Engine Light Codes P0420 and P0430. Replacing a catalytic converter or "cat" has become a big, expensive drain on a lot of people's …My stepdaughter chevy cruze is throwing this code. Any clue as to what it could be on this model 2014 Ltd 1.4. 0. ... P0420 Code; P0430 Code; P0300 Code; P0455 Code; P0401 Code; P0172 Code; P0446 Code; P0011 Code; P0340 Code; Automotive Features toggle close features. Driving; Lifestyle; EVs and Hybrids;You may ever experience troubleshooting, such as P0420 Chevy equinox. It happens after your car is connected to the scanner. The code appears to indicate there …Aug 10, 2018 · When there is a large leak in the Chevy Equinox’s EVAP system, it will throw the P0455 OBDII Code. P0455 indicates a large leak in the evaporative emission control system. (EVAP). There are different leak size codes. For example, P0456 means your Equinox has a small EVAP leak. While the trouble code may state that there is a “large leak ... Code p0420 chevy equinox, If your Chevy Equinox is displaying the code P0420, it means that the catalytic converter on your vehicle is not functioning properly. The catalytic converter is a key component of your vehicle's emissions system, and when it's not working correctly, it can cause increased pollution and damage to your engine., What does OBD code P0420 mean on a Chevrolet Equinox? This code basically means that the engine's O2 sensors associated with your Chevrolet Equinox's …, The P0420 code signals a low catalyst system efficiency. This code suggests that the oxygen levels are below the desired threshold (Bank 1), which most often results from problems with your car ..., Dec 27, 2022 · Common Reason: Code P0420 is often related to a bad catalytic converter. P0420 means the catalytic converter is not efficiently removing pollutants from the exhaust. Your car won’t pass an emissions test. A bad catalytic converter isn’t a hazard to the driver but it can overheat and destroy engine components. , Apr 5, 2021 · From the 2014 GM Repair Manual for both 4cyl and V-6: Start and idle engine for 3 minutes, high idle will start to decrease to normal. Ignition off for 60 seconds. Start and idle engine for 3 minutes, Drive and watch for normal idle, repeat procedure if necessary, clear all codes. , 2012 Chevy equinox 2.4L at about 135K miles threw a fan belt about 6 months ago on a road trip. Limped it to a dealership for fanbelt replacement and they said the timing chain was making a lot of noise and need replaced too. So I got it back home and had a shop do the timing chain with new tensioners and guide vanes as well as new …, What Does the P0420 Code Mean? Diagnostic trouble code (DTC) P0420 stands for "P0420 Catalyst System Efficiency Below Threshold (Bank 1).". It indicates that the exhaust system's oxygen levels are below the required threshold in Bank 1, which can damage the engine's exhaust and fuel system., Watch on What Does Chevy Code P0420 Mean? Chevrolet P0420 definition : Catalyst system efficiency below threshold (Bank 1) Issue Severity: MODERATE - Extended driving with this code can cause internal engine damage. Repair Urgency: Get this code fixed as soon as possible to avoid further damage to your emission system and possible engine damage., Code P0420 Description. The Engine Control Module (ECM) uses sensors mounted in front of and behind the Three-Way Catalytic Converter (TWC) to monitor its efficiency. The first sensor, the air-fuel ratio sensor, sends pre-catalyst information to the ECM. The second sensor, the heated oxygen sensor, sends post-catalyst information to …, I have a 2011 Chevy equinox, these codes keep coming up p0138, P0341, p0420, p0340. I had issues with jerking when idle, - Answered by a verified Chevy Mechanic We use cookies to give you the best possible experience on our website., Jun 20, 2022 · Code P0420 Chevrolet Tech Notes. As the code description implies the P0420 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (it is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases, the catalytic ... , Before you fix P0420, make sure you correctly diagnose the cause of the code first. If you don’t, you could end up spending $1000s buying a new catalytic converter when that wasn’t the cause of the code. Below are some of the main causes of a P0420 code. Click on sections below to learn more about each repair. , If you’re experiencing a p0420 Chevy Equinox engine code, there are a couple of common causes. The oxygen sensor and the converter are often the culprit, but there are also other causes. Misaligned exhaust functionality or a faulty catalytic converter can also be to blame., What Does Chevy Code P0420 Mean? Chevrolet P0420 definition: Catalyst system efficiency below threshold (Bank 1) Issue Severity: MODERATE – Extended …, This includes the Chevy Equinox. VVT adjusts the position of the camshaft (s) to maximize the combustion efficiency of the motor. P0014 means that the camshaft position is too far advanced from where it should be in relation to normal operating specs. Before doing anything, check your Equinox’s oil level. Low oil is the number one cause …, What Does Chevrolet Equinox Code P0300 Mean? Chevrolet Equinox P0300 definition: Random, Multiple Misfire Detected Issue Severity: SEVERE – Stop driving immediately Repair Urgency: Fix this code immediately (same-day if possible) to avoid ignition failure, catalytic converter damage, and dangerous conditions Diagnosis: A …, P0138 is the OBD-II code that is recorded when a high voltage signal is detected from the downstream oxygen sensor in bank 2. Read on for more. ... I would like to know where the are sensors located on the 2011 Chevy Equinox cause my engine light is on. 0. Reply. Leon Bryan ... P0420 Code; P0430 Code; P0300 Code; P0455 Code; …, P0172 is thrown when the oxygen sensors detect that the air-fuel mixture is too rich. A rich fuel mixture contains too much fuel in relation to air. The A/F ratio for ideal combustion is 14.7 parts air to 1 part fuel (14.7:1). With that in mind, either too much fuel or not enough air can cause a vehicle to run rich., One of the most misdiagnosed check engine lights is EVAP codes. Most people feel a new gas cap will fix the light. In some cases, they are correct! if you ar..., Catalytic converter replacement. How to replace a catalytic converter DIY with Scotty Kilmer. Catalytic converter replacement in your car (Code P0420). Tips ..., Mar 26, 2019 · Conclusion. P0506 is a serious issue. Due to the unsafe nature of driving with an engine that can stall at any time, we recommend having your Equinox serviced as soon as possible. Good luck! P0506 is a common OBDII trouble code. It is typically triggered when the engine idle speed is lower than the predetermined limit set by the manufacturer ... , Before you fix P0420, make sure you correctly diagnose the cause of the code first. If you don’t, you could end up spending $1000s buying a new catalytic converter when that wasn’t the cause of the code. Below are some of the main causes of a P0420 code. Click on sections below to learn more about each repair., Jun 4, 2018 · P0420 code will clear itself if after several drive cycles the computer sees O2 S2 creating a voltage consistently above 0.5v and only going below that during a throttle closed "coasting". Under load (driving down the highway, climbing a hill, acceleration) the voltage of O2 S2 should be consistently high and not drop below 0.5. , As a 2014 Chevy Equinox owner, you know that your vehicle is an investment. Taking care of it properly can help you get the most out of your car for years to come. Here are some tips to help you maximize the life span of your 2014 Chevy Equ..., Re: 08 Equinox Sport P0420 code NIGHTMARE Where did you purchase this car - a Chevy dealer, another dealer, or a generic used car lot ? 2018 Equinox LT1 1.5 L 4 cyl, AWD, S/R Cajun Red Tintcoat/Black 2010 Equinox LTZ 2.4 L 4 cyl, FWD, S/R Cardinal Red/Black, Apr 30, 2021 · =====Claim your FREE engine code eraser 👉 https://free.nonda.co 👈== How to Fix CHEVROLET P0420 ==Engine Code CHEVROLET P0420 Savin... , How to diagnose code P0420 Here’s a quick rundown of how to troubleshoot and diagnose the P0420 engine code: First off, make sure that P0420 is the only engine code present. Clear the code and drive for approximately 15 minutes. Check to see if the code is returned. If not, repeat the process a few times to be sure. , The most common P0420 and P0430 cause is a clogged catalytic converter filter, which requires replacing the entire catalytic converter. Other causes can include: A faulty or failing o2 sensor. Catalytic converter leaks. Exhaust , intake, or mass airflow (MAF) sensor leaks or other issues., Connect an OBD2 scanner and look for any related trouble codes that could cause the P0014 code. If you see any related codes to the crankshaft position sensor or camshaft position sensor, you want to diagnose these first, which could solve the P0014 trouble code. Check your engine oil level and make sure it is good. If it is low, add oil or ..., There are many potential causes of code P0016. Stretched timing chain. Jumped timing. Slipped reluctor ring on the crankshaft. Slipped reluctor ring on bank 1 exhaust camshaft. Faulty timing chain tensioner. Low/dirty oil. P0016 is not one of the top 5 trouble codes for the Chevrolet Equinox but, it is still a common one., Feb 21, 2022 · Common P0420 Diagnosis Mistakes. Oftentimes, this code is thought to be a faulty O2 sensor or A/F Sensor. While this is a possibility, the most common problem is a faulty catalytic converter. Do not overlook other codes that are paired along with P0420. Codes like P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, and P0308 are misfire ... , Short fuel trim is the immediate response of the ECM/PCM to rich and lean conditions reported by the O2 sensor. A Closer Look at Fuel Trim. Fuel trim isn’t something that can be read with an oscilloscope or meter – it must be reported to a scan tool by way of the datastream., 2013 Chevy Equinox - 86k miles - 4 cylinder - otherwise in good shape. Started burning oil last year - realized it and started making sure it was topped off - but now the P0420 code has popped up. took it to a shop who gave me a quote between 1600 and 1800 depending on the part used to replace the front CC which is a ****ton of extra work.