Hi All,

I've been troubleshooting a problem with my 2000 4.0 Explorer for about three months now. I got the code P301. I took it to Autozone and they recommended a tune up. I changed the plugs, cables, PCV valve and the light disappeared. About two weeks later the light came back and the Idle got rougher. I checked the coil pack and it was OK, ( I took it off and put it on my Friends explorer and no issues). I also changed the the fuel filter and I'm still having the problem. Now, I'm changing the injector on Cylinder 1 and see if thats the case. Does anyone have any ideas in case this does not work.

I really want to avoid taking it to the dealer because we all now how high that bill can be.


Please Advise, I'm going on my third month. Its my wifes car and she drives it around with my toddler son.

Thanks

 

Rgarces, as you know, code P0301 is "cyl 1 misfire detected". Sine you've already checked the coil and changed wires, it has to be either the #1 injector or spark plug. My money is on a bad sparkplug on cyl 1. The PCM will trigger a MIL if it detects two misfires on two successive starts, so the plug is probably firing intermittantly.

I'd change the sparkplug first.

Let us know how this turns out, and welcome to FTE!

EDIT: Oops, I see you've already changed the plugs. That only leaves a sticky injector........(Unless the problem showed up after the plug change. I've gotten bad plugs right out of the box before......)

 

I had this on my Mountaineer about a week ago... the code was 0308 and they solved it at the shop (it had another code which was an EGR valve that I did not want to change by hand) by replacing the #8 plug.

Hope that is of some help.

 

Lone Ranger,

Thanks for the welcome. I forgot to mention that I also changed all 6 spark plugs. Hopefully the new injector will solve the problem.

 

Hope it's not your problem , but the misfire code can also be brought on by the presence of coolant in the cylinder---head gasket or cracked head!
Angelo

 

ISSUE RESOLVED!!! It was the injector. After changing the injector, rough idle is gone and the check engine light has cleared.


Thanks,

 

Congratulations on fixng it, Rgarces. And thanks for posting back the solution. It adds to our data and may help someone else with the same problem.

 

I've got a P0301 code that came up yesterday on my '97 F150 Scab 4.6 131k.
Should I change the plugs and wires first? No COP on mine, early '97.
If that doesn't work, I'll look at the injector. Does this sound like a good plan?
Oh wait, maybe I'll get a stethoscope first and listen to the injectors to make sure they are working correctly.

 

Sounds like a good plan. Let us know what you find out.