I have a 97 F250 HD with a 351w, I have custom dual exhaust with 2 super 40s going out dual tips under the rear bumper. I have a k&n filter setup and some other stuff. I put a diablo chip in my ecm awhile ago and it worked good, I took it out and now my truck doesnt feel or perform and different. My mileage is the same as well. I put the chip back in and nothing happened, do I possibly have a bad ecm? I dont have anyone in the area who works on ecms so Id have to get a whole new one from ford, thanks for any help--Dinty01

 

Did you get the chip from MotorHaven.com? If so they can test it. If not, take it back to the dealer you got it from. Before doing either, disconnect the battery for about 30 minutes to reset the computer and see if that makes a difference.

 

I forget which website I got it from, but I sent it back to diablo and they sent me a delta chip back with 2 flashes on it and a toggle switch instead of the 1 tune chip I sent them. It worked good for a bit but I went back to the original problem I had, I dont notice any difference between any of the tunes, so Im wondering if its my ecm? Thanks for the reply--Dinty01