Well, I searched regarding this and couldn't find what I was looking for, but I was wondering if it would be a bad idea to add a 3" Buschur turboback exhaust with a high flow cat and Magnaflow muffler when I was custom tuned with the stock exhaust. I knew it was too good to be true to be satisfied with what I have, but I am so tempted to do this. My main concerns would be if the TBE would cause me to run lean (run low 11's regarding AFR's) and if it would cause me to spike higher than normal boost (I spike 21lbs and then drop down to 17-18lbs by redline). Boost is controlled via my ECU.

Thanks.

 

i believe cat back is ok. The ecu must account for the missing cat.

 

Well technically a cat is still going to be there, but its going to be a high flow cat.

 

RNM, I highly recommend NOT doing that. Do not get custom tuned on the stock exhaust then add a TBE.

 

gonna have to get retuned if you do the exhaust