A week ago I ordered a new BBK 75mm throttle body and a K&N intake kit. Installed both and after doing so the Service Engine Soon light came on and the truck seemed to be running in "protective mode". If you hit the gas all the way it wouldn't downshift all the way etc...

So I said the heck with the TB and put the stock one back on. Same problem. I can't image the K&N would be a problem? I can't see any leaks in the system. But I still have that stupid light on and my truck runs bad.

Any ideas??

Thanks for everyones help.

2001 - F150, 5.4, Supercrew

Chris Russell

 

reset the computer, its an after market throttle body so id assume its not used to it and so it thinks something is wrong, causing safe mode, happened to me when i got new transmission they forgot to re-set my computer, prolly all you need to do

 

Yea I've tried that a few time. Still a problem. Guess I'll try going to AutoZone and see if I can get any details on the error...

 

Did you install your throttle position sensor correctly? Did you break it? those are just the worst possibilities

 

Yea it ended up breaking. It wasn't springing back anymore. I got a new one at AutoZone and all is well. It's great AutoZone offers that free code testing. It really helps out.