So yesterday i was driving back from San Angelo, Texas to Killeen,Texas. While i started to reach around 70mph my 2004 FX4 (5.4L) started to skip and sound as if it wanted to shut down on me. I slowed it down to about 50-55mph. My emission light was blinking for a few moments then it stopped. I turned off my truck for a while at a little town to ask for a auto parts store (which there was none.) and when i got back on the road it didnt skip anymore. Does anyone know what may be wrong with my truck?? Any info would be greatly appreciated.

 

I think a coil going bad will produce those symptoms but I am not sure about the engine light. The engine light on my integra comes on when my catalytic converter is not cleaning the exhaust.

I have also bought bad gas that has produced the symptoms that you are describing.

 

Have the codes pulled, should help identify which cylinder is misfiring.

 

Thank you to those who have replied. My friend that works at an auto parts store also said it could be the coils, and or sparks, and catalytic converters. I also had the codes pulled.

They read as follows:
P0301 - Cylinder Misfire

P0171- System too lean, Bank 1

P0174- System too lean, Bank 2

P0191 - Fuel Rail Pressure Sensor CKT/Range
.................................................. ..............................

So Basically i dont know what this says lol. any help??

 

If you want to determine if it's one of the cylinders or plugs, use a pair of insulated or plastic pliers to pull off the spark plug wires one at a time. If the engine rpm's drop, that cylinder is working. So, put the wire back on and go to the next cylinder. Do this for each cylinder. If the rpm's do NOT change, that cylinder most likely has a problem. I did this on my integra after I hosed the engine and determined that only 2 cylinders were working because there was water around the spark plugs.

If you find a bad cylinder, the problem could be a bad plug, plug wire, injector, or wire connection to the injector. I dont think it is one of those problems but that will help you determine if one of the cylinders is not working properly. You can also do a compression test, but again, that is most likely not the problem.

It sounds like a coil to me, but I don't know if there is a way to test a coil.

UPDATE: This is how to test a coil. http://www.mymopar.com/coiltest.htm

Kevin

 

Thanks to those who have replied. It is greatly appreciated.

 

Is that the engine that shuts off 4 of the injectors at cruise speed to conserve fuel? I have a friend who had an Excursion wiht the same problem, Ford ended up replacing 3 or 4 of his coils!