Originally Posted by Volasko
When it comes down to it, higher flowing headers should not reduce you MPG. Having less back pressure in your exhaust, which makes more HP at the top end should actually increase your MPG. And an engine that makes more HP with roughly the same ignition parameters should reduce how much fuel you need to go the same distance. I doubt the AA tune is adjusting for the free flowing exhaust setup and dumping that much more fuel into the intake.
I can't comment on the off-road AA tune or the headers but something seems off. I am not trying to hate I'm just trying to help!
yes sir i know im just to the point of thinking this was a bad idea but i wont this was a good idea! ive replaced coolent temp sensor oil temp sensor swaped mafs with my buddy and replaced both pre cat o2.s so im stuck i need to see my A/F to see what the cars doing at idle. cause i can let it sit at idle for 10 mins and watch my mpg meter on dash drop and drop and drop and drop till it hits 6mpg it stays solid till i start driving then it picks back up so thats kinda tricky to me u know.. what i was thinking is at cold start the o2's dump fule to warm up the car so im thinking its not clicking off warm up cycle on the car so idk i may be talking out of my ass at this point but who knows