I have an ’02 with 190,000 miles The car started misfiring occasionally on takeoffs and under heavy acceleration; it has progressed over time about 3 months (10 miles a day). Now it happens almost always on takeoffs and any time the throttle is more than 1/2 way, yet it will still get up to 70mph without a problem, it just takes a while. I have multiple engine codes P0300 (Multiple Misfire Detected), P0301 (Cylinder 1 Misfire Detected), P0303 (Cylinder 3 Misfire Detected). I have checked and rechecked the plugs and wires and replaced the ignition coil as well as adding dry gas, premium fuel and injector cleaner (to rule out bad gas). I am out of ideas I don’t want to take it to Hyundai, the dealerships that I have delta with have been thieves! But that may be my only hope. Any advice would be helpful
Misfire Cyl 1&3 on 2002 Hyundai Accent
by jdgardella in Buffalo, NY on April 09, 2009
ANSWER by Bret Bodas , April 09, 2009
Driving a vehicle with a misfire can and will damage the catalytic converter, so hopefully you haven't done that. Here is a pretty good diagnostic tip for these problems: Since the misfire is always in the same cylinders, you can try moving components from the bad cylinder to a good cylinder to help locate the problem. Move spark plug #1 to cyl #2, take coil #1 and move it to cyl.4, reset the codes and if the code moves to cyl #2, the plug is bad, #4 and the coil is bad. You can try this with the injector too, just can't change too many parts at once or you wont be able to determine where the fault lies.
ANSWER by Visitor , March 30, 2010
I have a 2000 accent and I am having the exact same issue with it.. I have replace the plugs and wires as well as the coil pack and the issue remains. My code is for misfire on cyl 3.. please post fix if you find one before I do..