My 02 Civic has 114000 miles. The check engine light began coming on in late October 07. The light comes on after my car has been sitting while I am at work. It does not come on while I am actually driving. So far my local mechanic replace fuse panel, don’t think I needed it. My dealer gave it a tune, replaced all spark plugs and did a fuel induction service after getting codes p0303 and p0301. The car has since been back to the dealer twice, 2nd time they got the same codes and reset it. The 3rd time they did a ECM/PCM Software Update. I had the car back for 5 days and now the light came on again. Any ideas?
Codes are cylinder one and three misfire. Did the mechanic replace any ignition coils?
And or spark plugs and wires?
They did replace spark plugs, don’t know about wire or ignition coils.
This engine has 4 ignition coils. One ignition coil on each spark plug. This is an ideal situation for test-by-substitution. Since #1 and #3 are misfiring, and ignition coils are prime suspects, exchange #1 ignition coil with #2, and #3 ignition coil with #4. It takes about 15 minuets to do the swaps. After the swaps, take your car to Auto Zone and have them to erase any trouble codes. Drive the car for 2 or 3 trips to the store, wherever. Have the check engine light scanned. Now, if there are codes P0302 and P0304, that shows that the misfires moved with the ignition coils. Thus, the ignition coils are the culprits. If the misfire codes are still P0301 and P0303, the ignition coils aren’t the problem and further troubleshooting will need to be done. If there are no trouble codes, be sure to ask about any “pending codes”.
They assure me that the coils have all been tested and are fine. The misfire codes are still the same. Anyone want to buy this car. I used to love it, but now I am so frustrated by the double talk of service people dealing with it has become a nightmare.
Ignition coils can be checked for proper resistance and STILL be defective. Two cylinders don’t misfire. Two cylinders DO misfire. A test by swapping is the ultimate test…and it’s so easy to do!