Cadillac STS-V Series Forum Discussion, Still chasing down engine code! in Cadillac V-Series Forums; Ive replaced bank 2 sensor 1 because the codes called for it. I was hoping this would end the issue. ...
Ive replaced bank 2 sensor 1 because the codes called for it. I was hoping this would end the issue. I cleared the code and the light popped back on. I have two codes now. P0430 and P1074 which indicates cat and maf I believe. Anyone have this problem or know for certain whats going on before I replace everything. I also have a pretty good oil leak on the back side of the engine. Dont know if this is fouling out sensors or what but everything is covered in oil.
Automobile(s): 2006 STS-V and 2007 STS-V The Murdalac
1/2 hr S of Grand Rapids, MI
Re: Still chasing down engine code!
Everything on Google says the 137 & p2a01 code are a bad secondary o2 sensor. Either that or the car is really plugged up. Does the car run ok? swap the secondary o2 sensors side to side and see if the code swaps sides too.
Before replacing an HO2S, or for that matter a Catalytic Converter, especially for a P0430 code, remove the post-cat HO2S and clean it with some electronics cleaner or brakekleen. This is a code that is typical of a post-cat HO2S not move up or down (in it's mV readings), even slower than it is supposed to, in relation to the Pre-Cat HO2S's. 9 times out of 10, you can save yourself some serious $$$$, just cleaning it out, resetting the PCM and seeing if that fixes the problem. Unfortunately without a Tech 2 or other suitable diagnostic tool, you can't simulate the I/M system test that generates the P0430 code after you do this to see if the problem comes back, so you're left to normal driving, letting it run it's test(s), and seeing if it flags again.
If you have a Tech2 or similar, I would turn off all electric/electronic accessories (radio, lights, etc), manually turn on a low speed cooling fan, then raise the RPM's to about 1,500 rpm's and hold it there for 5 minutes. Then let off. The Post-cat HO2S, should start fluctuating slowly again, the system will run the I/M test for P0430, and if that HO2S is flucuating properly, it'll pass. The reason you need to turn on the fans before doing all this, is while you're holding it at 1,500 RPM for, anything turning on, can cause a slight load variations, which would then potentially cause a change in the mV readings of the Post-Cat HO2S. So you want to negate this before hand.
But as mentioned, looking for any post-MAF air intrusion can also cause this.