my 2004 f150 4.6 has acheck engine light on. flashes sometimes while on the highway. I know it missfiring. Considering changing the spark plugs. Any suggestions?
17 Answers
Yes, a flashing check engine light is a indication of a miss fire, and if not taken care of, can cause damage to the catalytic converter. Spark plugs, and wires are the first thing to look at, then try to isolate the miss, may be a coil, or coil pack that may be bad and can be tested at an auto parts store.
Thank you. I plan to have the codes checked today and try to determine which one(s) are misfiring.
Ok, so I changed the number 7 coil. Truck runs great now! Reset the pcm. Ran for almost 500 miles. truck still running great but engine light came back on stating crank sensor. I am going to check the wires first. Any other sugguestions?
Yes, just check out the wiring, lot of times it is just a bad connection at the plugin. Check the plugin at the cam sensor also, the system is tied together so to speak. Another cause is if the sensor gets too far away from the reluctor due to rust. Just check it out.
I hope it is that simple. I have heard that changing the crank sensor is a not so easy task. I will take a look at cam sensor wiring as well, that one is easier to get to. Thank you
Your welcome. If it comes on down to it, the crankshaft sensor can be tested.
Yes unfortunately. You run 12 volts threw it and it becomes a magnet.
Thanks. Let's hope it just a loose connection or something like that then.
Ok. Crank sensor code is gone. Now a new code is up. P0430. The for what could cause this is a long one. Any suggestions on where to start
If the engine has ben running poorly, a miss fire, this damages the catalytic converters just below the exhaust manifolds. The catalytic converters need to be changed out, especially if you truck needs to pass emissions. P0430 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be replaced to fix the problem. If the P0430 code is combined with other codes, try fixing the other codes first. Here is a video to watch on this... https://youtu.be/xLyytQD7njw
I am eligible to get truck tags in my state. With these emissions is not required. I may do that until I can get enough together for a new catalytic converter
Would I need to replace both or just the one on the side that the misfire was on?
I am not sure if the "Y" pipe is two piece or not. They say cats last up to 150,000 miles, you may want to replace the upper two cats. Check with an exhaust shop on this one.
