Hello all and thanks for reading. Got a couple questions that hopefully someone here can answer. Came up with a way to set up custom exhaust but not sure if it will work. I'd like to start from just after the downpipe with 2.5" pipe straight back and a high flow cat (or no cat if I can get away with it) and muffler. I'm planning on having the stock 02 sensor bungs welded onto the new pipe and using 02 sensor spacers to fool the ECU so I won't throw codes. Is this sound logic? If it is can it work without a cat? Keep in mind I am not chipped, also I surely don't want to run too rich or lean. The car is a "96" 850R.

Thanks in advance

 

You can use a spark arrestor to pull the O2 sensor out of the exhaust stream. People use these to run without a cat.

http://www.fastwrx.com/sparkarrestor.html

 

Go to your local auto parts store and get 2 spark plug defoulers for a few bucks. Drill one out with a 5/8 inch bit and then screw them together. Put the defoulers in the rear O2 isensor port and then screw the O2 sensor in. Did this one my SR and never looked back.