sS07NA

Car has a slightly rough idle and the dealer said my p300 is a old code. My question is, with full bolt ons with no tune would it be the cause?? Thx

Verbatim

iTrader: (1)

Info on car?
-mileage?
-year?
-Auto/manual?
-any maintenance work?
-specs on full boltons?

Can be anything underhood causing a random misfire code which is a vague code anyways

sS07NA

Cobalt 2.4
110k
2007
Manuel
Ive replaced the clutch already and master cylinder twice.. if that helps.
Intake, throttle body, header/dp, exhaust, flywheel

Jacob4ta

iTrader: (1)

Try swapping around coil packs and see if its coil pack related. Just unplug the cylinder that's misfiring and swap it with another. See if the misfire follows that pack.

Check spark plugs and make sure they're not old as heck, fouled and are gapped properly, .044"? I believe?

Also, you mentioned throttle body as a bolt on. Are you tuned for a different throttle body?

sS07NA

Spark plugs are good, I was trying to fix the misfire first so I can tune it. Would one coil throw a p300?

Jacob4ta

iTrader: (1)

P300 is multiple cylinder misfire. If the ecu detects multiple misfires, it wi throw that code. Usually with a code read you can narrow down which cylinder is bad.

Verbatim

iTrader: (1)

p0300 is an engine misfire...not necessarily a multiple cylinder misfire
I would start with a scan tool that can read cylinder miss history and go from there before i even pop the hood

sS07NA

Thx guys