Thread: 01 gtp misfire and rpm drops

Current mods:

3.4 mps
180 tstat
Speed daddy headers
Egr, cat & ubend delete
3" dp
magnaflow mufflers
ngk iriduim plugs and prj wires
custom tune by zack
new coils
k&n intake
zzp tb spacer

started yesterday when driving and come to stop or just idling rpm drops and goes back up. Had the window down and heard it puff in the exhaust so maybe a misfire. Happened before when i had AL104s. Thought it was plugs changed to iridiums.. But happened again. Could it be the wires gone bad.. Please lmk asap

Kinda vague here really...any check engine lights?

A video of what is happening?

You should be running colder plugs on a smaller pulley...not factory iriddy's.

AL104's...gapped at .050-.055"...also...get rid of that TB spacer that is doing you nothing good but causing the rear bank of cylinders to get hotter than the front. How did the plugs look when you pulled them out before hand?

No check engine.. Plugs looked ok no signs or any damage

Random question...since you don't have a cat...are you running an o2 sim?

not sure if they put one in when they did my headers, etc... ill check it out this afternoon when i get home from work... i dont think so they just tuned out the cat and kept stock o2 sensor

It's an '01+ car...they can't tune out the cat diagnostics AFAIK.

It also started holding back at full throttle..

got the throttle issue fixed but still misfiring at random times, put new plugs al104s gapped at .55, new oem wires, new pcv value, fuel filter and oil changed, replaced the coils before when this first started happening then one plug went bad and it was ok at first then started doing the rpm drops. throttle body spacer gonna be removed tomorrow... any thoughts

Vac leak at the TB spacer?

They are junk afterall.

Also...what do you mean by "one plug went bad" ?

It was crack when took the boot off

Same issues im having. Same exact mods except spacer

Sometimes car feels sluggish then other times its fine.. Not sure what could be.going on... Would i have to do a retune since i changed from ngks and msd wire back to al104s and oem wires

Any thoughts on what it might be