hey guys im trying to figure out why my car is running really rich i can really smell the gas out my exhaust now it wasnt like that befor .
so far all ive done the car is cone filter instead of big box thing, ive moved my ecu to under dash and i no longer have a resonator on the exhusat and a cat from a ford truck and the cat is 3" compaired to the rest of the vehicle which is 2 1/2 i think ??? and suggestion on how to fix it would be greatly appreciated i would like to see more then 350KM to a tank.

First off, I'll bet that catalytic is the wrong size for your engine. You can't just throw any cat on something and expect it to work right. 3"? What did you get it from, an F-series? Try having the proper size cat installed & see what happens.


Go beyond the "bolt-on".

kool thanks will try that.

any codes? sounds like an 02 sensor, size of the cat shouldn't matter, there are people running without cats and not having any problems.


-Chris