I only have a narrow band a/f guage. I don't have a cat. I deleted the cat u-bend and resinator. There is 3" pipe there now. Ok I've gotten rich and lean comments. I know I'm running rich because the guage says so and I smell it in the exhaust. I will be putting the stock pulley back on for sure!! And get different plugs also! Would a 3.4 pulley be good? Thank you all for your feedback!!! More would be great!! I'm also putting on an egr delete plate. Would this help too?