I was awarded the P0308 code last night after my 2001 4.6L began to miss and the "Check Engine Light" illuminated. This code represents a misfire in cylinder #8. After performing a search on this board, it seems that the COP is a likely culprit.

Is there a way to test these coils before dropping $100+? I know I can replace the spark plug first to rule it out, but am wondering if there these COPs can be tested (i.e., resistance test) like the old coils. If so, what is the procedure?

Thanks,
Jeff

 

I have the 5.4 and I was told you could'nt test them so last night I started replacing the coils and plugs,WOW what a pain so far I've got 5 out of 8 done. but I did find a good price at NAPA for $41.00 each.

 

Thanks for that tip. I was told by Autozone that the coils were a dealer-exclusive item.

-Jeff

 

They sell a node tester for COP testing , Also with a simple multimeter check the (+) terminal connector to the spark boot inside connection for a 5.2 - 5.6 resistance

 

Does the wire/spring actually slip onto the spark plug tip, or does it just sit above the spark plug and not snap onto the spark plug tip?🤔

 

The spring is directly connected or attached to both the COP and the spark plug electrode---its the only way the high voltage spark gets to the actual spark plug.

 

Since this necro thread got bumped up. If anyone has this problem again. Just swap it into another position. If the misfire moves, it's bad.

 

Got rid of the misfire codes, but still have PO171, PO174, AND 405 and rough idle a little better but not like it should be! I don't know what to do or what the problem could be. Have replaced: 8 plugs, 8 coils, cats, muffler, exhaust, 02 sensors, cleaned throttle body and intake manifold! Cleaned MAF sensor too! I'm lost, need help and desperately to say the least!