I just had the coils replaced on my 2001 F150, 4.6L V-8 because it was cutting out on acceleration. The new coils fixed that problem beautifully but in about 15 minutes the Service Engine Soon light came on. I had it checked at Autozone and it showed a P0176 error code, a malfunction in the electrical circuit for the fuel composition sensor. The engine runs great but idles a little rough, not much, but I can tell it is not a smooth as it was.

The truck has just under 93k miles on it and has a manual transmission. My question is, would anything the mechanic did when installing the coils cause this? Loose wire, broken wire or connector, anything? Or is it just coincidental?

Then, has anyone else had this problem and what did you do to fix it? Any and all help and advice is gratefully received.

 

Your truck is flex fuel, right. This code is possible a bad flex fuel sensor or check connection. I have no idea where it's located but I would start searching around the fuel tank.