97 Grand Prix GT po171 code and abs light

[Jonarin]

I got my car in april of this year with 133xxx miles and currentlyhas 138xxx. When I first got it, the cel was on for po171 code (system too lean). The guy told me it was a o2 sensor. He has told me he replaced the upper intake manifold. I then found out he never put a new pcv valve in it. Put it in, cleared the code and never came back on. This month the code came back on. I just cleared it but it still didnt come back on... any ideas?

Second, my abs light, check tire press light and trac off light comes on all the time. I had advance auto scan that and they couldnt retrieve the code. They told me it was definitely not a wheel speed sensor. I definitely thought I could find out which wheel speed sensor was bad and replace the wheelhub. How do I find out whats wrong with it? Thanks

 

[nik12937]

Out of curiosity, did you put the o-ring on the PCV valve when you installed it? It has an o-ring that you normally just transfer from the old valve when replacing, it can cause a vacuum leak if it's missing.

There has to be a code if those lights are on, as the code triggers the ABS/TCS lights. The person at Advance either didn't scan it correctly or their scanner cannot read GM ABS codes. I'd try bringing it somewhere else to get scanned, even a dealership as a last resort (since they may charge you labor). You're correct in thinking the code would show you which sensor is bad. The only other possibility is the ABS control unit, which is unlikely. Whatever wheel speed sensor it points you to, check over the wiring going to that wheel before replacing the wheel hub. Bad wiring can cause the same issues as a bad wheel hub.

 

[Jonarin]

I put the o ring on it. It came with the new pcv kit