Cel for coil c after o2 sensor replacement

[hmr83687]

Hey all so I’m doing some work for a buddy, and I changed out his bank one position 1 o2 sensor. Well now that it’s back together we are getting a code for ignition coil primary and secondary fault for coil c. I don’t remember the exact number sorry. I’ve tried swapping coils around to see if it’s the actual coil but it isn’t. This leads me to thing wiring because the plug is good too. I just don’t know where to start. Like how do I make sure that it’s getting signal, power, and ground. I’ve double checked all the wiring for the o2 sensor. I did have to drop the exhaust to finally get to the o2 sensor after having broke about 3 crows feet. I’m not getting any exhaust leaks either. I’m just stumped and have no clue on where to go from here. Thanks guys!

Also we haven’t driven it because the misfire sounds super bad. I don’t know if that help at all.

 

[bodabdan]

I have to ask what prompted the O2 sensor replacement?

 

[hmr83687]

It was throwing a pending and permanent code for that O2 sensor. The codes now cleared, but now that new code for the ignition coil is coming up.

 

[bodabdan]

To be honest it's kind of a crap-shoot without the actual DTC codes.
O2 sensor codes can be the result of a bad sensor but can also be the result of a different component having problems and forcing the O2 sensor to give a wacky reading.
Any time things don't make sense, verify everything starting with the basics and assume nothing.
Your description of primary and secondary coil codes makes me think that anything short of a lightning strike probably wouldn't kill both sides of a coil at once. I'd look closely at grounds and maybe even manually ground things with a jumper wire to see if symptoms change.
I'm not positive but I suspect that a bad coil would also show some misfire codes.
It's also possible that a code you see now was set at a different time under different conditions and was just never cleared.

 

[hmr83687]

So I figured it out. Well, Kinda I had cleared the codes multiple times and it was still coming up as a pending. I believe it was P0303? Not exactly sure. Anyway, what I did was disconnect, the whole passenger side bank of coils and cut the zip ties holding them to the valve cover to get more length in the loom. Next I stuck a super small pick into each of the connector holes and bent down the tabs a little bit and then sprayed some electrical cleaner inside and reconnected them next to make sure that the negative/ground cable to the battery was clean I put it back together and it’s solved the issue. I also think that from when they were done last, the previous mechanic broke one of the clips to the ignition coil, and it didn’t clip down all the way. Thank you!

 

[bodabdan]

Glad you got it figured out!