Bad gas milleage

[Chewy676]

Okay so i had a magnaflow exhaust but it wasn't loud enough for my liking.. So i cut off the pipes all the way back to the cats and gutted them out, Sounds alot louder now, But ive noticed now im getting very low gas mileage even with mileage xs tune from my cortex tuner. Also i have 2 engine light codes which are the o2 sensors & a running lean code. What could i do to fix this ? o2 simulators or would it be better to just buy new cats and weld everything back together? Because my mileage is really low now

 

[usaf2006]

The o2 nonfouler trick should work. There's a write up here somewhere.

 

[Rampitt]

what gas mileage are you getting right now? Im getting 13.3 mpg

 

[blackbeautyhemi]

Yea hope the defoulers work for you cause they didn't do **** for me