SOURCE: code po304 #4 cylinder mis fire
ck if you have spark at the coil for that cylinder. check the plug wire closely. if it has spark at the coil, then replace all the spark plug wires.
SOURCE: trouble codes
A code P0304 may mean that one or more of the following has happened:
Possible Solutions
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.
Code P0316
i've heard of the 5.4l's with the "cop" set up devolping moisture under a coil. if it hasn't again that is most likely the problem. to prevent this you could remove each coil and apply dielectric grease to the tops of the plugs.
SOURCE: 1998 Ford Explorer, 4.0 SOHC No
You are at thhe right trail what controls spark is coil pack crank sensor sparkplugs and plug wire but the most important is power . I mean 12 volt connections and ground This includes checking fuses you need a simple volt meter doesnt have to expensive or fancy just to pick up 12 volts let start with fuses in the engine juction box (there not mark to what it belongs to) make sure none are open. especially fuse 19 and 24 , next go to the crank sensor make sure the tabs are snuggly on now to the coil pack there is a red and light green wire this comes from ignition and feeds 12 volts at the coil pack measure that voltage is it 12 volts if not correct it this is from ignition switch ( you can make a tool that feed 12 volt with a wire and a fuse in series and attatch it to battery and the primary wire this is known as hot wire) next go to the ECM wiggle the wires see if that get a connection going if not go back to the ICM here are the wire you are to measure the tan light green, this is from ECM and it is pulsed it measure 5vlts to 0 volts switched then measure the tan orange the same thing 5 volts to zero,then tan white again 5vlts to zero. any one of these 5 to zero fails you fix is the ecm
SOURCE: 2002 saturn vue cylinder 1,3,5 misfiring when swapped coil pack it went away now cyl 2,6 misfiring.
having PO 304 = Misfire cylinder 4,PO 306 = Misfire cylinder 6, as I read above you have done the most. The thing that you have missed is to check whether the Catalytic Converter is faulty or not. To get an idea check whether you have a smell like rotten eggs at the end of the exhaust,you start having problems with cat and needs replacement. My advice before you go for a cat replacement is good to visit an MOT center and check your emissions and then you decide,
Testimonial: "I have been having this problem for a few months now and I have tried everything except install a new Cat. I had a feeling but wasn't sure until this guy mentioned it. He really knows his stuff. He pin pointed everything to a "T". You're a really good mechanic, my friend. Keep up the good work. Thank you so much. Your knowledge is highly recommended."
214 views
Usually answered in minutes!
×