Hello all brand new to the site and had a few questions. I got a 98 tahoe with a 5.7 and was wondering if i take my cats out will it increase power and give me better gas mileage?? I understand it is frowned apon for emission reasons but i am just wondering what the pros and cons would be. I have built a few go fast cars before but oudveiously was not concerned about gas mileage. so i was wondering on this motor would it help me gain power and gas mileage with them out. or one or the other. thanks for taking the time to read my post any input is appreciated thanks

 

Welcome to the forum
Probably not as they create needed back pressure, engine performance can be adversely affected by removing them...not to mention you will have a constant check engine light and won't pass emissions testing if your state has it or starts it...
try removing the exhaust right at the headers/manifolds and you will see how crappy it runs... sounds cool thou

 

Welcome to the forum.

I agree w/ in2pro. If you're interested in reducing back pressure, then you should look into hi-po cats that are freer flowing, headers, and a catback exhaust. But w/o better intake flow which would require head work and bigger valves and hi-po intake manifold you won't achieve much.

But a good tuneup w/ the correct OEM parts is probably the best way to go.