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P0420

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P0420 OBD-II Trouble Code: Catalyst System Efficiency Below Threshold (Bank 1)
P0420 code definition Catalyst System Efficiency Below Threshold (Bank 1) What the P0420 code means The catalytic converter pulls in the pollutants that are expelled by the cylinders and uses oxygen...

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Question
Codes P0420 and P0171 appearing
When it relates to the air conditioning system, the dealership does not have an advantage when it comes to hybrid air conditioning systems. These air conditioning systems require special evacuation machines that are different from that of a normal air...
Question
Check engine light code P0420
You may have a purge valve that is leaking and causing excessive fumes to enter the intake manifold during the refuel process. When you start the vehicle, the excessive rich mixture may be causing the catalyst to overheat which will...
Question
Can a defective catalytic converter cause clutch failure?
To answer your question, a catalytic converter cannot cause clutch failure. You have a series of independent failures, which is not very common for vehicles with less than 100,000 miles. I would take your 2013 Chevrolet Cruze back to the...
Question
P0420 code after idle relearn
Hello. P0420 is the code for catalyst efficiency below the correct threshold for bank 1. If you do not believe the catalytic converters are the issue, then the first thing I would do is check the bank 1 oxygen sensors....
Question
Engine misfiring 2003 Honda CR-V
Misfires can be caused by several things. I would first check for vacuum leaks, then I would pull the plugs to see if they need replacing. It is possible that have a fuel system concern, but I would lean more...
Question
Code p0420
Hello. P0420 could be due to a variety of faults including even a fuel pump that is not supplying sufficient fuel, causing a lean condition, and hence "fooling" the O2 sensors (pre and post) as to the status (i.e., efficiency)...
Question
Very hard to start vehicle
Hello. This code is also related to the catalytic converter not working properly. This can also happen when the ground wires connected to the O2 sensors are not properly hooked up causing them to send erroneous info to the computer....
Question
I have the P0420 code
Hi there, thanks for writing in. Code P0420 has to do with the catalytic converter in your vehicle. The code will need to be diagnosed by checking the vehicle for exhaust leaks, O2 sensor problems, or the wiring to the...
Question
Reading P2096/P2098/P0420...in the past these have came up but are not clearing this time.
The P2096 and P2098 codes are for both of the downstream oxygen sensors. The P0420 code is for the bank one catalytic converter efficiency. It would be best to have a certified mechanic take a look at the vehicle and...
Question
How to get more horsepower without the check engine light and still still pass smog
Coming from a realistic point of view, I'd say that unless you were to pull your motor and completely rebuild it, from pan to fuel injection, you might want to consider NOT adding components for horsepower. With over 200,000 miles,...
Question
The engine light is on and the code is P0420 - Catalyst System Efficiency Below Threshold Bank . What part do I need to fix it?
While a number of things like a faulty oxygen sensor or exhaust leak can cause fault code P0420 to be set, the most common fault is the catalytic converter itself. However, as a replacement can be very expensive, your best...
Question
Check Engine Light is on - trouble code P0420
As you may know, trouble code P0420 relates to the inefficiency of the catalyst system, which detects the presence of oxygen in the exhaust gases. This can be caused by failing O2 sensors that need to be replaced. This can...
Question
Check Engine Light on - P2187 and P0420 codes
Hello. If I understand correctly, when you say "catless downpipe," you mean that you have installed a pipe without a catalytic converter. If that is the case, you are always going to have the code for catalyst efficiency. The...
Question
Po420 bank1
Hello Tom. P0420 is the Catalyst System Efficiency Below Threshold (Bank 1) code. While there are a multitude of components that can cause this code, the general concept is that your catalytic converter is not working properly. If you suspect...
Question
P0420 - CATALYST B1 DETERIORATION
Hello - it is possible the 2 problems are related, but likely only over a long period of time. The P0420 code is a "low efficiency catalytic converter" for Bank2 - which include cylinder 1. And yes, that warning is...
Question
Misfire and P0420
Hello - the P0420 and the inconsistent waveform for the post-cat O2 sensor might be related to your failing intake manifold gasket issue. If tiny droplets of coolant are being sucked into the engine - one failure mode for this...
Question
My car shows a P0420 code and the engine coolant temperature reading (via torque pro app and elm327 Bluetooth reader) stayed at 84.2 degrees
Hi there - "boundary measured engine temperature," or the lowest temp reading a sensor can transmit, can be different based on each temperature sensor. The issue here is what is the true engine temperature? Is the thermostat getting the engine...
Question
p0303, p1313, p0420. codes come up. no flashing and now signs. what do I do?
Hi there. Sounds like there are a few things going on. First the code P1313 means that the timing chain has jumped a tooth making the camshaft and crankshaft out of sync. The chain tensioner may need replaced if it...
Question
p0420
A vehicle with 182,000 miles is likely due for a catalytic converter. Most of the time it does mean you need a new catalytic converter. But there are a couple of other things that are prudent to take a look...
Question
My car shows trouble codes P0133 and P0420
Hi there: It appears as if you've got a lot of miscommunication going on with your mechanic. Here are a few basics. First, anytime an error code is triggered, such as the P0133 OBD-II code the issue needs to be...

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