I have a 2007 h3. I recently had to change the oil pressure sensor. I figured while doing that it was time to change my plugs again, I have about 191,000 miles. After changing them, it had a misfire. Had codes read and it showed a cylinder 5 misfire. Checked things,so decided to change the coils. Cleared all codes, still had a misfire. Checked code, same code. Any ideas what changed?

 

if the parts where bought from amazon/ebay there is a high probablty that they are counterfit parts.

 

Plugs were bought at O'Reilly & Coils were bought at Autozone

 

check and make sure that the plug does not have a hairline crack. i have had autozone sell me cracked plugs in the past. stockboy drops them then just puts it back on the shelf. if you cant see a crack then move it to another cylinder and see if the code changes to that cylinder. if it does not move then swap the coil to another cylinder and see if the code changes. if it stays then maybe you have carbon buildup on your valves.

 

Welcome to HF.

MOVED to the H3 section where all H3 questions go. The Forums Help & Suggestion section says at the top to NOT POST ANT VEHICLE QUESTIONS there. That is for help using forum features, got nothing to do with any vehicle.

It would also help if you posted the actual code, not a fancy interpretation of what you think it is.

Check the harness and its connector to coil on plug pack for #5. Do you have a can of CRC Electronics Cleaner? Everybody with an old vehicle should have one. Disconnect the offending coil, inspect the truck side for corrosion, spray the connectors, let dry, reconnect and see what you have.

If that is not it, do an induction/intake cleaning.

Good luck

 

What plugs did you use? This engine seems to only like the OEM plugs.

 

I just told my son that. He put in rapid fire. I told him to go exchange them & get the right ones & see if it changes. He tried to argue about it but I reminded him that I was the one that taught him & his brothers how to do their first oil change, not his dad (I had to teach him also). It just too hard for me to do it anymore. This is 2nd day he has had it & I'm still waiting for him to do it. When he does it or if I have to go & try to do it myself, then I will let everyone know.

 

It was the plugs. Changed them, no more misfire. Thanks everyone

 

 

Very true