Alright it is a 97 f150 sb,sc, 2wd with the 4.6. It had a problem with the motor feeling like it was going to stall out (never actually stalled) when you drove it, the only code that was thrown is for misfire cylinder #4. To tell you what I have done so far, New plugs, wires, coil pack on driver side for cylinder #4, cleaned the throttle body, new MAF sensor, DPF sensor(I think thats what its called, litlle flat box with 2 or 3 rubber hoses going to it) , Cleaned the AIH sensor. The truck ran fine for a couple days then the check engine light came on again and it started stalling (motor actually cut out) this time is still stalling What am I missing, I have searched this site and was unable to come up with what I am missing. Can anyone help before I drive this into a lake? Thanks in advance

 

Same code the 2nd time?

You mention replacing some wires. What wires?

If it's still #4 and the wire you replace was from the computer to the COP, then the injector is next although I'm not sure the code would be a misfire if it's an injector problem. With injectors you usually would get a P12xx or P020x code.

 

Yes it is the same code both times. I replaced the plug wires, from coil to plugs. If I remember correctly it was a PO340 or 304 I can't remember but I do know for a fact that is was for misfire cylinder 4. Is there a easy way to test the injector to find out if it is bad?

 

It doesn't have COP's it has coil packs.
P0304 is #4 misfire which is the rear cylinder on the passenger side. Check your heater hoses for a sign of a leak. They have clamps in that area above the plugs and can drip antifreeze into the plug pockets and short out the wire.
You can usually ohm out the injector to see if the coil in it is good. Ohm it and the one next to it and see how close they are.

 

OK. The 4.6 has (2) 4 wire coil packs.

 

stupid question what is ohm? And how do i do it. Thanks

 

Resistance. You need a digital multimeter to do that.

 

Ok borrowed a digital meter, can I unhook the plug and test it or should I leave it plugged in with the engine running? Thanks again for the help

 

I have cured more p030x codes by cleaning the fuel injectors than I ever have by changing plugs wires or coils. The injector should have about 14-15 ohms of resistance. To check it you have to have an OHM meter disconnect the plug to the injector then touch one lead to one of the pins on the injector and the other lead to the other then read the ohm meter. if it reads lot lower then 14 then it has gone short it it reads alot higher or will not come off max or OL (depending on meter type) the the injector is bad. Good luck