michiganfootball911

iTrader: (3)

Just changed all 4 sprak plugs today. They were pretty burnt. 25k miles.
Installed new NGK 5476. Everyone said they come pre grapped. Seem to be around .35

Issue before was backfire (would pop a few times) under WOT only.
Issue now is under ANY pressure the car while completely studder and barely go.

Whitnith

iTrader: (2)

Neve heard of that plug for a Cobalt before... Could be your problem. NGK Cobalt plugs start with BRK or ILT...

michiganfootball911

iTrader: (3)

they are ILTR5D 5476

Whitnith

iTrader: (2)

Those are the stock LNF plugs then. Should be pregapped and good to go. Don't know what's up then. Sorry.

outtamymind

double check the gap. even though they say pre-gapped, you should always double check the gap before you put new plugs in just to confirm. also if you've done mods then your gonna have to play with the gap a bit to find your motors sweet spot.

eanoller08ls

iTrader: (3)

^^^ true story ALWAYS check!

michiganfootball911

iTrader: (3)

They were all gapped to about .35. I changed them to around .31 and nothing changed.
What to do... take it to dealership? im tired of doing this ****

outtamymind

well what motor do you have and what mods do you have? i know someone mentioned LNF earlier but confirm that that is what you have.

Chevycobaltss3

iTrader: (2)

well u have a bad plug then if u changed them and now u have issues

michiganfootball911

iTrader: (3)

yup. LNF. zzp tuned. zzp intercooler, pipes, intake.
They were brand new plugs. Ill try another set i guess.