I just bought a new exhaust and yanked out the cat.

The check engine light is on now as expected. I was wondering if it affects the gas mileage. And if so how much does it affect it.

Any input would be great.

THanks.

 

Won't know until you run the code to see if its the primary or secondary o2. If its the secondary, no effects other than the CEL

 

isn't it usually the secondary that throws the code when you pull off the cat.