2002 SS 102,700 Miles


My check engine light came on today and I scanned the codes with our hp tuners scanner and I need to rack you all's brain. Here are the codes exactly as displayed on the scanner:

[PCM] P0420-Catalyst System Low Efficiency (SES) (OLD) (History) (Current) (Immature)

[Unknown] B2650-(History)(Immature)
[Unknown] B2651-(History)(Immature)
[Unknown] B3069-RF/LF Door Key Unlock Circuit Low (History)(Immature)
[Unknown] B3128-(History)(Immature)

I think the [Unknown] codes are actually BCM codes. I have been having issues with my gauges resetting randomly while driving and I wonder if any of these have anything to do with that? Do any of you guys know much about codes? I read the OBD thread but only saw like one or two of my codes listed and still don't really know what they mean lol. I am new to our HP scanner and I don't know if it could help me troubleshoot this more or not but I figured I would ask the awesome Monte Carlo community we have on here. Any input is greatly appreciated!

 

Good chance you have a clogging Cat from the P0420, OR that oxygen sensor has gone bad, OR you have an aftermarket cat and it doesn't run in the threshold of the OEM parts.

If you have an aftermarket cat and you know the cat is fine, you are safe to delete that code from the PCM.

 

Thanks for the information. As far as I know the cat is the stock cat. The car still runs fine other than the check engine light. What would be the best way to tell if it is the cat or an oxygen sensor?

 

Get the cat tested at an exhaust shop

 

Or if you smell rotten eggs, that's a bad cat

The other codes are BCM codes, seems like it could be failing

 

Here are what the codes are.

 

Thanks for the info. No rotten egg smell and the car still runs fine. I'm not sure what to do. I guess I will keep an eye on it. The other night when I started the car it sounded like the exhaust was rattling for a minute or two. Some one said that could be the cat as well.

 

Thank you! I did have my high beams go totally out on me one night. They kept going off and on the whole night. It has never happened since either..... I also had my door lock switches unhooked for a while when my door panels were off. Maybe that explains the door lock codes..?? I hope this doesn't mean a bad BCM. My gauges like to reset on me randomly too when I am driving. The car dings and everything like it does when you start it. I can't afford a CAT and BCM......

 

Well having your switches unhooked could lead to the codes, maybe disconnect the battery for 30 mins and see if the codes are still there.

 

Sounds to me like the switch being unhooked threw the lock codes. I would look for a short in the head light circuit, you definitely don't need a BCM.