Hey guys, I know this is my first post and all, so please don't attack me cause I'm a total newb. I have been lurking in the shadows for awhile quietly, I just never had much to contribute.

Anyways, here's a short run down of what's been going on. I have a 2002 A4 1.8L Quattro @ 182k that I've been the owner of for 5 years. My car lost most of it's acceleration and thew the MIL light a month or so back. Took the car to the stealer, and they suggested new cat and crankcase hoses, as the codes wouldn't stay cleared and they could see it really lost its power. Had the cat, hoses and check valves replaced (not at the dealer, but an indy shop) and drove fine for a few days. MIL light came back on and I ran the codes with VCDS again. Same codes came back again after maybe 20 miles. These codes are the same that I pulled when I took my car to the dealer the first time.

I initially thought maybe I needed a new pre-cat o2 sensor. The only thing is, the code thrown shows as Bank 2, Sensor 1? There's so much reading I've done on here and my mind is maybe a mess right now, but isn't it that my car only has a Bank 1? Would I be looking at a bad ECU then?

Any suggestions are greatly appreciated.

Thanks,

 

Oh, and I wanted to add too that when using a generic hand OBD-II scanner there's a change in codes. I still get the cat threshold code in generic form, but I also get a "system too lean" code, which isn't present in VCDS. The hand code scanner as you can see is also missing the o2 sensor code.

And on another odd note, I pulled the saved codes I had from a scan on June 9th, and there was another odd code in VCDS that was thrown that also wasn't on my hand code scanner at the time and shouldn't apply to my car.

After that clear I never saw it again..

I don't know what I'm dealing with here. Bad ECU? VCDS not working correctly? Any ideas?

Thanks,

 

I always thought one closer the the front and one farther in the back. And one of them is a real pain to change.

 

Well I know theres a front sensor, sensor 1 precat and rear sensor, sensor 2 postcat.. But on my car I should only have a bank 1 right? This is claiming the fault is at bank 2..