Was wondering if I can gut the precats without any problems from the engine management??? I dont like their location and they cause high heat and reduced flow, I know on my 04 audi S4 it made a noticable difference in power and didnt effect emissions. I plan on keeping the main cats just since I was in there thought if the engine management isnt going to wig.

 

You're referring to the cats directly below the manifolds, right? if so, you'll get a check engine light. The O2 sensors measure before-n-after exhaust on those cats so you'll get a "catalyst efficiency fault"....P0430 and P0420

How the engine management will respond...I'm not sure.

I used to have a P0430 issue (had to replace exhaust manifolds) and the car ran fine...but the system thought the car was running lean so it wanted to richen the mixture.

Actually having the cats gutted, though....I'm not sure what will happen. Someone with a better brain will chime in.

Unless the cats are *clogged* you probably won't gain much, if any, power. I haven't heard from any XJR/6 owners having much luck with power increases via less exhaust restriction

Cheers
DD

 

sounds good Doug no worries I dont want any codes still have to pass emissions lol