P0158, P0174, P1153 Consistently...

**jfl330** · 04-03-2012, 06:10 AM

I replaced the 2 rear O2's and still get the same codes.

P0158 says rich (rarely goes under 800mV), P0174 says lean, P1153 says not switching frequently enough.

Only bank 2, and brand new O2 did not help. Cats are only a few months old, GM replaced both under warranty.

Could this be a bad PCM? No idea what to do next. Replaced intake manifold gaskets, replaced PCV system.

Help would be appreciated.

Jon

**JayTA98** · 04-03-2012, 06:50 AM

Have you cleaned the MAF sensor? Have you checked for an exhaust leak or vaccum leak? you mentioned you replaced bothe rear o2's. I'm assuming these are brand new. Have switched the new o2's with each other? you could have a bad one.

Were the codes showing prior all the work you did?

**jfl330** · 04-03-2012, 07:32 AM

Originally Posted by JayTA98

Have you cleaned the MAF sensor? Have you checked for an exhaust leak or vaccum leak? you mentioned you replaced bothe rear o2's. I'm assuming these are brand new. Have switched the new o2's with each other? you could have a bad one.

Were the codes showing prior all the work you did?

I cleaned the MAF a few 1000 miles ago, if it was MAF related, why is everything bank 2 related? Replaced the entire PCV system not too long ago, fresh hoses, conenctors, elbows, etc.
Brand new Denso O2's in all 4 places. Yes, codes there prior to O2 replacement.

GM replaced the 2 cats a few months ago, so I have not checked for exhaust leaks, but other than manifold --> head, where else could it leak that would matter?

Jon

**0rion** · 04-03-2012, 07:57 AM

have you inspected the sensor harness and wiring? Also.....take the plug off the pcm and check for corrosion. Sounds to me like you have either a bad connector, corroded connector, chaffed wire, or something like that. I stop short of saying bad pcm because the pcm's are pretty durable units so it would always be the last thing I would look at replacing but at some point you may have to look at it also. I would start with those connectors on the pcm and see if any of the pins are corroded. I've seen that happen and it's not uncommon.

**JayTA98** · 04-03-2012, 08:00 AM

sounds like you checked everything. I have no experience with denso o2's but im sure they should work fine. The only leak i could think is by the exhaust mainfold. Have you trace the o2 sensor wirring and does it looks okay? It could be an issue with the PCM. Im sure some other members will chime in.

**JayTA98** · 04-03-2012, 08:17 AM

Originally Posted by 0rion

have you inspected the sensor harness and wiring? Also.....take the plug off the pcm and check for corrosion. Sounds to me like you have either a bad connector, corroded connector, chaffed wire, or something like that. I stop short of saying bad pcm because the pcm's are pretty durable units so it would always be the last thing I would look at replacing but at some point you may have to look at it also. I would start with those connectors on the pcm and see if any of the pins are corroded. I've seen that happen and it's not uncommon.

damm orion beat me to it lol.