When the cats are cold, yes. Warm, not so much (unless the car is running rich). HP gains will depend on how the car is set up (ie: do you have headers, an X pipe?, Tune?)
I gained 12rwhp with the addition of SS cats. The sound is intoxicating as well. :cool2: With my soon to come Alpha N and power tune from Evolve I will have better gains as well.SS headers and X-pipe with there rear cans too. Running stock cats. So without the cats and the proper tune(???) and the rest of my exhaust what kind of gains do you think can be expected?