Check Engine light

I am having issue with error codes. On my Ultra gauge it every once in while tells me P0420 and P0430 codes but does not throw the engine check light. So yesterday I changed the down stream 02 sensors and now I am throwing p06060 code. Any suggestions would help.

 

P0420/430 are catalyst efficiency codes, basically the computer looks for the downstream sensors to switch from rich to lean much less and slower than the upstream sensors to determine if the catalytic converters are functioning properly. If your O2 sensors are good and you have no exhaust leaks it's likely your catalytic converters are no longer functioning properly. Not sure about the other code I think you have an extra 0 somewhere because p06060 isn't a valid OBD code.

 

No CEL? So if you delete your Ultragauge, your problem would disappear?

 

sorry it is P6060

 

That code description indicates a pcm internal issue (not from memory, i just googled the code description)

Its trying to say the internal logic doesn't agree. Often times its a clear sign the pcm is faulty.

What type of 02 sensors did you use? Universal? Denso? If something on a 02 sensor circuit was hinky it may confuse the pcm somehow.

 

Still have the original sensors? Put them back in and see what codes come back

 

Agreed on the O2 sensors since that code came up just after replacing O2 sensors, you might test your battery too, I've seen low battery voltage cause module internal errors and other weird codes.

 

i put the sensors back on but havent not fired it up and drove around to see what codes pop up

 

So I drove it this morning with then original sensor in and no check engine light. But ultra gauge gave me p0156 code.

 

What brand of 02 sensors did you use when you replaced them?

The p0156 and the previous 420/430 could all be lazy 02 sensors. But you also need to look for any air leaks in the exhaust pipes near the cats/sensors

At work we see a lot of 02 sensor failures and we don't overthink it, but technically you should be checking wiring harness integrity from the pcm to the sensors (and back). That involves pinning out wires at the pcm connector, checking resistance, etc.

Id say keep going with 02 sensor replacement but with good quality sensors. And understand that you may still have a cat problem (p0420/430) when its all said and done. And hope you don't see that pcm logic code again

 

thank you for your help and responding.