I put a gibson swept side exhaust on my 2001 F150 4.2L V6. It made a noticeable increase in horsepower and drove great but caused the engine to idle very rough while in drive at a stop. Park idle was fine. I put the stock system back on and it fixed the idle in drive problem but at an obvious cost in HP. I want the HP back. I don't want a system that gives it a spastic sewing machine sound. I do tow a trailer so I need the low end torque. Can someone help?

 

hey , mike told me about your truck ... thats really weird . when i talked to him yesterday , he said that he was installing the kit on his truck right now . haven't heard from him yet , i don't know if it worked or not though . i will probably call him later today because i am fixing to install one on my truck as well and want to make sure there is no problems with it either .

 

hey wade: the gibson swept side made that much difference in hp and torque for pulling a trailer? would like to give my truck a little more umph for pulling. it's done well so far with dirtbikes but this year we've decided to try snowmobiling.

 

Well...your truck should be able to tow the weight of snowmobiles, like there not even there, without any mods. I tow a 4400LB travel trailer and the FIPK and exhaust help alot. Just dont go too big on your exhaust pipe. Also you can try gears...I got some 373's.