2002 GMC 2500 van with a 4.3. 212740 miles. Code P0430 popping up all the time. Cannot find vac. leaks, exhaust leaks, changed cats and O2 sensors. I did weld on after-market cats, with the required distance for the O2 sensors. Any input? O2 sensor bank 2 downstream seems to have alot less voltage then the others.
Country: United StatesMake: GMCModel: 2500Year: 2002Engine: 4.3
renew cats, o2 sensors. check vac and exh. leaks
Hello, I'm Cam. Please include all the details about your issue so I can accurately advise you. I cannot see your vehicle so please be detailed.
This code is a very specific code. It relates to the operation of the catalytic converter chemically. It is monitored by the post converter oxygen sensor.There are systems that must pass for this code to set, specifically the oxygen sensors must pass their own self tests to set this. Second this must fail twice in a row to set this code. All of this means that the rest of the system needs to be working or it will not set and it eliminates the sensors.So the fix is simple, and that is to replace the catalytic converter. There are many aftermarket options, but time and time again the aftermarket ones tend to fail far too soon after making the extra cost of the OEM one a wise choice to consider.
GM Grand Master Technician 2007. 11 year experience.