R1ch

iTrader: (4)

I recently had a problem in which my driver's side O2 extension fell onto my header and burned causing my car to run like crap. I replaced the extension and had codes for both O2s so I replaced them with brand new Densos. For a while I was still having the driveability issues. The car would drive fine on first start up but after about a mile it would start to feel like it was misfiring under 2000 RPMs under acceleration.

I eventually reset the PCM and the problem went away, but recently it's been doing it but not as bad. The car drives fine on startup, then starts to miss a little, then throws a P1153 code for the passenger side O2 insufficient switching. According to the wideband the car dumps fuel but when this happens the car drives great, just runs rich.

I have brand new exhaust clamps and don't see any leaks. The driver's side is fine and not throwing codes but the passenger side is.

Any suggestions on what could be causing this or what might fix it?

BLK02WS6

iTrader: (2)

Sounds like your headers are leaking... cheap headers often leak where the primaries come together into the collector - due to poor welding. When you first start it up, you are running in open loop so the leaks don't effect it. Once it warms up, it goes into closed loop and the leak effects the way it runs because of O2 feedback. Also, the leaks will sometimes get worse when the pipes get hot...

The only way you can find some primary to collector leaks is to have the car idling up in the air and get under there. Because it is in between the tubes, it won't be easy to see/hear...

Seen it many times - one of the main reasons I always recommend good headers - you get what you pay for...

JonCR96Z

iTrader: (33)

Try switching sides and see if the code follows that O2. I've had similar issues with a dirty (wet) MAF.

R1ch

iTrader: (4)

Never really thought of that. It probably doesn't help either that the header on that side seems to hang lower than the other and is all scrapped up from hitting speed bumps and things. I'll take a look at that this weekend.

I have some other O2s laying around so I'll throw one of those in and see if that changes anything.