I am looking for some help to figure out what may be the problem on my truck. Ive had it for about 5 months now and have loved it so far but got in it yesterday and it had a miss or skip to it. Went and bought some spark plugs and changed those and still having the problem. Had the parts store run a check on it and it said crankshaft sensor, cylinder 3 misfire, gas cap, and another one that they said could be bc of my gas cap also. A little about my truck. Its a 2002 F150 FX4. Has 119,000 miles on it. Its a 4.6L 4x4. I just had exhaust put on it and not sure if that might have caused a problem. I had flowmaster y-piped into dual exhaust. Thanks in advance for any help.

 

Original COP's?

 

how about posting the actual codes..

 

Coil pack 3 was replaced before by previous owner.

 

Codes were P0303--P0316--P0455-P0457-P0171-P0174...

 

You have a vacuum leak somewhere. Check all vacuum hoses. Apparently its bad enough for the evap system not to be able to pull enough air hence the 455/457 codes. The 303/316 codes will probably clear up when the leak is fixed. Check the PCV hose, the hoses coming off of the evap vacuum solenoid located on the firewall driver side. Basically any rubber hose connected to the intake would be suspect.

 

P0303-P0316 = coil #3. It's getting real bad, - since you have these DTC's together.

Don't worry about the 171/174 yet, - fix the coil first then reset the KAM/memory.

PO455, the filter canister is plugged. Go to the back of the solenoid and pull the tube and cap off the back. Just leave it disconnected and the DTC will go away.

The deal is, Ford discontinued most of those canisters for these trucks. They catch all the gases when the fuel cap quits working. Thing is, you can replace the fuel and still have the problem. Does that make sense ? I'll explain further, -

This is what you remove, the back of #9 -





There's a canister and a filtered hose leading elsewhere. The canister plugs up, everything is shoved thru the filtered tube. If that filter also plugs up, -you get a PO455 regarless if the gas cap is venting.




This is what it looks like after removed, -

 

thanks guys ill jump on it this weekend and let you know what i come up with. Ill replace that coil #3 and check the other stuff you guys suggested. Thanks alot