help with engine code PCM 0420
Thread Starter
Racer
Joined: Aug 2007
Posts: 335
Likes: 14
From: Fort Wayne Indiana
help with engine code PCM 0420
Just bought my 02 Z06 and it pulled the code the next day out of the garage. I am not familiar with the definition of the code and what TCW bank one out of alignment etc, etc, etc even means. Depending on the fix i would like to do it myself instead of a dealer having to charge me all the labor. Can anyone tell me what the problem is? I read one thread about this code popping up afte LT's installed, but my car is still stock. Possibly an o2 sensor? Any help would be appreciated, otherwise i'll be calling the dealer in the morning.
Thanks!
Thanks!
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
It's TWC, and it stands for "Three Way Catalyst".
P0420 and P0430 are catalytic converter efficiency codes. P0420 is for the left side, P0430 for the right.
Simply stated, these code(s) are set when the PCM detects not enough difference in readings between the front, and rear (post cat) 02 sensors.
It could be a fluke occurance, it could be a bad cat, or, it could be a bad 02 sensor.
Before taking it in for this...I would reset the code (which will also clear the check engine light), and see if it returns. If it does return, then more investigative work will be needed. This code won't hurt your car or the performance, and if it continues, I would start by swapping the rear 02 sensors side to side and see if the problem follows the sensor or not.
P0420 and P0430 are catalytic converter efficiency codes. P0420 is for the left side, P0430 for the right.
Simply stated, these code(s) are set when the PCM detects not enough difference in readings between the front, and rear (post cat) 02 sensors.
It could be a fluke occurance, it could be a bad cat, or, it could be a bad 02 sensor.
Before taking it in for this...I would reset the code (which will also clear the check engine light), and see if it returns. If it does return, then more investigative work will be needed. This code won't hurt your car or the performance, and if it continues, I would start by swapping the rear 02 sensors side to side and see if the problem follows the sensor or not.
Premium Supporting Vendor
Joined: Mar 2001
Posts: 5,241
Likes: 21
From: Knoxville Tennessee
Before taking it in for this...I would reset the code (which will also clear the check engine light), and see if it returns. If it does return, then more investigative work will be needed. This code won't hurt your car or the performance, and if it continues, I would start by swapping the rear 02 sensors side to side and see if the problem follows the sensor or not.
Good advice.
Thread Starter
Racer
Joined: Aug 2007
Posts: 335
Likes: 14
From: Fort Wayne Indiana
ok stupid ? And sorry for not searching but how do I reset the code and clear the light? Do I need a tuner or somethingbor is there a fuse to pull? That is great info and may have saved me god knows how much $ now just to clear the code and I'll start playing!
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
Well, since you said you pulled the code (assuming via the dash readout), simply bring the code up again, and while it's displayed, hold the reset button for a couple seconds to clear it. It'll disappear, as will your CE light.
