New spark plugs fix backfiring issue?

[nikhsub1]

Just to update (since I said I would), I've filled up... well more times than I'd like to admit since my original post and haven't had any backfiring. I don't know if it's the colder plugs or the 0.031 gap, or the combo of the two, but that's all I changed. I also don't know why it only occurred on a full tank... but if you have the annoying backfiring might be worth throwing in a set of colder plugs gapped at 0.031 and see if it fixes it for you too. Hope it helps someone else.

Nope, doesn't help me. Still backfires, have change plugs 4 times but only when topped off. IDGAF about it though.

 

[Sunchild714]

So I was experiencing a pretty bad backfire issue after my recent trip to Baja. This weekend I changed to the NGK Cooler Spark plugs with .28 Gap and the backfiring is completely gone. I'm running a COBB Stage 2 tune package.

 

[Jaymare404]

This past weekend, my truck started experiencing a misfire issue, not exactly a backfire, but a really really bad shake under acceleration. Truck threw P0304 and P0300 codes. This was during an hour and a half drive home from the airport. I pulled over and pull the coil pack and didnt see anything wrong with it. It fixed the shaking issue but i decided to get to the bottom of the issue by changing plugs first... I pulled the non factory champion plugs that were in it, and checked the gap...

0.050

Bought some factory SP-550s from Oreillys and installed them... gap on them... 0.028...
I am not sure how long i was running with these not correct gapped plugs but man does it run a lot better and no more misfires!

 

[Sunchild714]

This past weekend, my truck started experiencing a misfire issue, not exactly a backfire, but a really really bad shake under acceleration. Truck threw P0304 and P0300 codes. This was during an hour and a half drive home from the airport. I pulled over and pull the coil pack and didnt see anything wrong with it. It fixed the shaking issue but i decided to get to the bottom of the issue by changing plugs first... I pulled the non factory champion plugs that were in it, and checked the gap...

0.050

Bought some factory SP-550s from Oreillys and installed them... gap on them... 0.028...
I am not sure how long i was running with these not correct gapped plugs but man does it run a lot better and no more misfires!

Damn! Those were way off. Are you running a tune? If not, .028 might be too small for you. I believe stock should be about .031

 

[Jaymare404]

Damn! Those were way off. Are you running a tune? If not, .028 might be too small for you. I believe stock should be about .031

No tune... but they were gapped iridium and most measured in that range. They were SP-550 plugs so they are the factory heat range too. It runs SOO much better now. No hesitation and no misfires. It also feels like it has more spunk too, but that may just be the placebo effect, or my butt dyno may need recalibration.

But I definitely agree about the gap being way off! i dont even know what those old plugs were recommended for. They were champion iridium 9901. Im guessing... and this is just a guess... but they were for 3.5L v6 NON turbo engines.

I havent put the truck through its paces yet with the new plugs, but i will be this weekend when i pull our camper to ohio for a weekend camping trip. Ill report back on the trip after.