Random misfires - Spark plugs changed
 

Hello all, first post here even tho i have been lurking these forums for years!

I own a 2016 370z and since my ownership 5 years ago, i changed the spark plugs twice, once was very recently (1 month ago). After i changed my sparkplugs, i don't get any misfires or codes. Yesterday i went for a drive and then my CEL(check engine light) started flashing, and it seems i have once again some random misfires. I drove maybe 500 km since i changed them and everything was working well.

-Car is tuned with ECUTEK for 94 octane (that's all i run).

I am wondering what could be causing this ? I was thinking the ignition coils but then again, if that was the issue i would be getting the misfires even after i change the plugs wouldn't i ?

Honestly frustrated because it takes forever to change the plugs and would prefer not to have to change them every 500 km or so... But above all, i am worried ill cause some engine damage...

Anyone has had the same issue and what did you do to fix it? Maybe the car is running to rich ?

If you need more info to help please don't hesitate!

Thanks in advance!

Yes, I have had the problem. I have EGT sensors on every cylinder so it was very easy to diagnose. I had installed some Z1 high energy coilpacks. As soon as I hit 16psi of boost it would misfire. It was very intermittent. Replaced all 6 coilpacks with factory Nissan ones and no issues since. If you can get a code that tells you what cylinder swap it with a known another cylinder and see if it follows.

I am in the same boat as you, except mine is tuned with Uprev. It finally threw code P0175 which is Fuel System Rich. Also corresponds with the fuel trim for Bank 2 going to -25.

Which mods do you have? A friend of mine suggested going back to stock exhaust from my Fast Intentions with LTH but I really don’t want to do that unless I know it will fix the issues.