My 01 v6 is currently sitting in the driveway with a p0305 code. Seems like the coil is the most likely culprit at this point since plugs and wires only have around 15k on them but will be tested anyway. I bought the car with just under 90k September of last year and replaced plugs and wires (41-101 delco plugs/omnispark wires) since the ones on there seemed to be the original ones it came with off the assembly line with the exception of one plug. I've been intending on replacing all 3 coils due to a barely noticeable constant rough idle and a 2 minute very rough running a couple of months ago. Question is, do I really need the seemingly overpriced delco coils? I'm looking at possibly BWD for about $37 from O'Reilly or Delphi for about $34 from Rockauto.

 

Tested coil, spark tester results were identical on all coils. Idle and revs are unchanged with plug wire disconnected. I'm unable to test the wire since the plug connector broke off. I guess it doesn't matter anyway since Oreilly is going to replace the wires under warranty. I was able to test resistance on the broken wire and got a stable 1235 ohms, I'll check the other 5 when I replace the wires to see if it's the same on all. I hope that's the problem because the other possible causes only get worse.

 

not a good idea to unhook plug wires without some place for the spark to go. did you hook a plug to it and ground the plug so it would fire.

 

Used a spark tester

 

kool, if wires are good look closely at the plugs, just takes a tiny crack.

 

I got new wires under warranty. Plug was intact, no damage or cracks and the gap was still spot on. 3 new coils should be at the house by the 3rd, 3 delphi coils, about 111 bucks shipped. I'm hoping the wires and coils resolve the issue especially since the original coils are corroded anyways.

 

could have got new oem d555 ac delco coils for $60 shipped on ebay

 

I never think to look for stuff on ebay. I got the coils installed and started putting on the plug wires only to find out the connector in the last wire was too far up in the boot to connect to the plug. I spent a half hour tring to move the boot up the wire to make it work before I gave up and pulled the other 5 out. Looks like another trip to the auto parts store after work tomorrow.

 

I had to travel halfway across town to get another set of wires under warranty but I'm up and running again. New coils have made a big difference, car's quicker now and I can't wait to see what my mpg does next week.