I think I found out what I'm going to do ^^, haha

advice taken though, I won't buy the cheap O2 sensors,

and Hxgaser, thanks for all the help, I think I'm just going to buy the driver's side CAT for now (I found two CATCOS online for $500, but I'll try to get one side for $250). I won't change the oxygen sensors yet, and I'll see what happens and if I get new codes.

Thanks for all the help

 

just to make sure though, which one is Bank 1??
I guess I should've asked that from the very beginning,
again this is a 2000 A6 2.8Q

 

As mentioned earlier, bank 1 is passenger side.

 

It is refreshing to find someone with sense of humor; good man.

By the way, you don;t live in Cali, do you? Some of the CATCOs are illegal for sale or use in Scwhartzie's state.

 

Thanks...& nope I'm not in Cali, why is everything illegal there? kinda weird

 

I have no idea... I came across that information while looking for CATCOS.

It sounds like they 're under heavy regulations... socialism border-line (sic!)... and under a Republican governor... don't know if that's any sort of a correlation

 

for 01 2.8 a6 i replace o2 sensor with universal one and was 65 $ at car parts store, but doesn`t have the plug , so i have to cut the original to use the plug and connected yourself. works fine. also u may try to messure the resistance for o2 sensor , can be tested with a meeter, is how u know if works, search for that. there are some post about it and they show u how to and what plug , everything .

 

I got the CAT online not too long ago, and was waiting for my mechanic to get some free time, now I got 2 things going on

1) I haven't been driving the car, except for very small distances, but when I do u usually never take it easy. This morning, the rattling noise of the CAT completely went away, but I got 3 engine misfiring codes, and the car is hardly accelerating. (it goes fast, just very very very slow and hesitant acceleration). I was in a traffic jam, tried to accelerate out of it, and the car almost completely stopped.

2) I got the CATCO CAT, but my mechanic wouldn't put it on. He told me that this one has the O2 sensor before the CAT, when it should be after. But I got it online with the exact same car description (does this sound logical?)