If I punch cats on my 2000 s4 will i throw codes? If so what can i do to avoid this?
I pretty sure i read somewhere that an aftermarket chip will ignore this but not sure wherei read it now.
Does anyone else have a tough time with this sites "search" option? cant seemto get any results out of it.

 

Vast CELimiators.

 

i have my cats completely gutted, not just punched, and im not throwing codes at all.....may just be lucky tho

 

Blue S4, did you notice a difference and power? if so, how much?

 

Sweeds4: If i gut the precats and get cel eliminators....will i still have to relocate and plug the O2 bungs? or can i leave them in their current location?
Also, will this method also work for the rear cat?

 

I dont think so, but check out the vast site, they might tell you on there.

 

I just did the piggie pipes and they were a PITA. But to answer your question, you canget the eliminators or relocate the O2's. Also since your already putting holes in the cats you should just take them out completly. Its hard work but pays off at the end when your making boost the second you touch the gas. Also you can hear the turbos a lot more

 

Relocating them is the better way. The car is better off with the info from the o2 sensors for air mixture and fuel mixture and good running order and all that. You get like a few hp doing it, butthe real trade off is instant spool for the turbos. Oh and its the rear ones you relocate and would getthe eliminators for you don't touch the front.

 

not in the seat of my pants....i did several things at once, but i can gaurentee it made a difference since my old ones were pretty messed up and melted.

 

First post... Hi everyone.

Do the rear O2 sensors actually relay information to the PCM for fuel mixture purpouse. Or are they there simply to enforce that the converters are working as they should. ie... the pre converter 02's take the readings for fuel mixture, the rear 02's just ensure that the converters are doing what they should, based on the difference in value read by the 02 sensor itself.

Mike