jag_off1

I have a 2000 A4 quattro that keeps tripping the mil lamp with cat codes. Right bank 2 i belive. so since i do not have emissions where i live i was wondering if i were to remove the cats an just have a straight pipe welded in how this would effect operation? seeing as there are 4 cats on these things. i believe 2 pre and 2 reg cats. any info would be great. thanks in advance.

Corrado_Guy

If you straight-pipe the exhaust by removing the cats you will get a little more power and torque but you will still get a CEL/MIL. There can be a number of things that can cause the CEL such as a weak cat or O2 sensors but if you remove either you will continue to get a CEL. You can use an anti-fouler on the post cat O2 sensors and this can reduce or eliminate the CEL as long as the cats are the problem. If you simply punch the cats by knocking out the inner honeycomb you will lose a bit of power and the exhaust will make a tinny noise. It is better to fix the problem because if your car doesn't have the cats it will pollute more and if you get a vehicle inspection it will fail.

AudiMick

There was an ECU reflash for the later 2.8 for this problem, if the cats and the O2s are OK check to see if the car was covered.

It's against Federal Law to remove the cat.

It's also illegal in many places to resell a car without declaring that emissions equipment is removed. Even if you don't have emissions inspections it's possible that some Zip codes in your state do, which means the potential resale takes a huge dump.

Unless you tend to drive it into the ground or track it (and who tracks a 2.8?)not a wise plan.