Sensor Codes & Prices
 

99 with 62,000 miles.

I had an intermittent problem with the car not accelerating properly and at times almost stalling. No CEL though. Car had been working fine for two weeks than CEL
Comes on. I get P1129, P0154, P1127.

Is it reasonable to assume this was causing my accelerating problems? Is my best course of action to replace all the o2 sensors? Anything else I should do or replace?

Also, I always use oem parts but Porsche sensors are $200 a piece. $800 seems kinda steep. Are aftermarket O2 sensors just as good?

Thanks!

Check the O2 sensors wiring first.

Since you have alarms on both sides "lean mixture threshold" I'm thinking vacuum leak. Have you ever replaced your Air Oil Seperator?

No I haven't replaced the AOS. I did the Cap "test" and it seem fine, also, the car ran rough with the cap off and clear up with it back on, not getting a lot Of smoke, maybe a little smoke on startup a couple of times a month. So you think it
Could be something other then the O2 sensors? Thanks.

Your car is running rich. It sounds like a possible bad MAF. From Renntech.org:
http://www.renntech.org/forums/topic/7558-p1129-odb-code/

Disconnect the MAF and drive the car. If it runs better, replace the MAF. Your O2 sensors are simply reporting the problem and are probably fine.

I did clean the sensor, which seemed clean. The problem is the car really has been running fine the past two weeks. I'll disconnect it and see if I can tell a difference.
I appreciate the input and ideas!

When you remove the oil fill cap while the car is running (eninge needs to be warm) the idle will increase a little if your AOS is good. It might idle a little rough but idle RPM's should go up a little. If the idle drops and runs real rough (almost stalls) you have a bad AOS. Was the cap hard to remove due to a lot of vacuum?

Cap easy to remove and the RPM's increase, so I guess the AOS is good. Oh well.
Thanks for the suggestion.

Have you performed Topless's suggestion of removing the MAF sensor to see if runs better?

I haven't yet, because right now it seems to be running fine. Im waiting for it to act up again. Intermittent problems are frustrating. Thanks.