UPDATE: Could it be cam sensoR????? Number one and four dead on coil pack?????? Hello new to Ford Forum: I have a 1997 F150 w/4.2 Liter so here is problem last weekend filled up with gas drove home about 8 miles. Went out later to leave and check engine light started flashing, and running rough, (Misfire?) po351 code would not pull its self. 1st thing done was changed out intake gaskets. 2nd coil pack, plugs, plug wires. Still no change shutters at idle, could it be a cat? After clearing code and all work to this point no check engine light or codes. Had truck scanned and everything show working correctly. Thank you

 

Maybe just got a batch of bad gas.

 

Put gas in our Exlporer at the same time and have had no problems.

 

If the cats check out and there is proper voltage to the coil, you might want to check out this thread then:
http://www.ford-trucks.com/forums/57...ode-p0351.html