I changed out my mid pipe and exhaust with an off-road h-pipe no cats and slp loudmouths. My check engine light is on now and I can't feel any back pressure and/or the air/fuel is off.

Where can I take this to get it fixed or modded?

 

you need a tune since you got rid of the cats.

check out americanmuscle and get a sf3 tuner. they give free tunes for life so when you upgrade, you dont have to buy a new tune. even if you purchase parts from other places.

 

+1 you need a tune.

 

Had you checked the forums, you'd have known this would occur. Order a custom tune and based on your mods they'll turn the rear O2 sensors off. The custom tune will gain you a lot more power than the O/R H is gaining you. Plus it'll make real use of that K&N which is only gaining about 3-4 RWHP without a tune.