C_A_D88

so i noticed my car idling a lil rough today so checked out my interceptor, says im missing on 1 and 3 ,

2.2 auto
gmpp catback
2.4 intake mani
^only mods i have that have anything to do with the engine

my question is, what has caused this, whys it missing and how do i fix it?

Topinka

you check the plugs?

Red2.4SS

Agreed... plugs most likely

ssblackstealth

iTrader: (8)

plugs and coil packs....

C_A_D88

I changed the plugs like a month ago used oem ac delcos , where can I get coil packs and how much they run? Btw I'm a 2007 with 113k kilometers

nikemax21

iTrader: (4)

Before you purchuse the coil packs swap 1 and 3 with 2 and 4 and see if the problem follows the coil pack. if it doesnt, then its not the coil packs and hopefully the plugs

C_A_D88

could the plugs be bad after only a month?

and i installed a 2.4intake mani last week or so, could that have any effect on it?

also it doesnt miss all the time, it happens randomly.

Phil424

Fuel filter. Its extremely rare to have 2 coils go out at the same time. Its not the plugs.

C_A_D88

i replaced the fuel filter about 6 months ago...could that still be the issue?

and turns out im missing randomly on 1,2and 3

Red2.4SS

Remove and check plugs. Make sure they are in good condition. Check the gap.

teri2280

Good luck. (Sorry, but that's all I've got.) Been fighting a misfiring/stalling issue on my 06 LT since freaking November. I've replaced fuel filter, cleaned (and later replaced) throttle body, new plugs, had fuel injectors cleaned (later replaced), and cleaned the MAF sensor. And she's STILL misfiring. Not near as bad as she was before the new injectors, but still enough to annoy the crap out of me. Thinking of trying another set of plugs here in a few weeks.

07cobalt_LT

check your wiring going to the coil packs, maybe your ground is bad, or loose

the ground bolts up the the back of the head by the valve cover.

teri2280

Update??? Still fighting my issue. Replaced injectors yet again (this time with AC Delco's), and she's STILL doing it. Based on posts on the ecotec forum, I'm thinking ICM and curious if you got this issue resolved.

C_A_D88

Nah I gave up lol it's not to bad and figure it's normal as I have read somewhere a couple
Misfires at idle are normal

Malaclypse

iTrader: (1)

Ignition control module and a coil cassette are both probable causes of misfires on the 2.2.

I've noticed another, more expensive problem with the '06s in particular, though Burned exhaust valves.

That's right. I've replaced about four or five cylinder heads for burned exhaust valves causing misfires on one or two particular cylinders. I suggest that anyone having problems with misfires who has eliminated the coil, plug and fuel injector to run a compression test to see where you stand. If you come up low (usually in the area of 100 - 125 psi) you may have one or more burned exhaust valves.

Coblasts

Have the ecm codes checked for history for misfires,if they were bad enough the ses light would flash.
Otherwise I dont think you need to worry about it,No engine is perfect and the plugs might be fouling a bit
Due to the engine running rich at idle.

teri2280

Not bad enough that my SES is flashing, but it keeps coming on after a couple of weeks (roughly 120 miles) of having it reset/repaired. Misfiring is bad enough that my car shakes when stopped at a light or sign, and it gives my tach a super low reading when slowing down - she'll drop below 500, and act like she's going to stall out - DID stall out in colder months, always restarted right back up, thank god - so this is def. something i've got to figure out. What exactly is a compression test? Is that the same as a leak down test?? (My hubby has the tool to do the leak down test....I wasn't too thrilled when he bought it, but I'll NEVER complain about him buying a tool again if it is the same thing...LOL.)

For some strange reason, I really do absolutely adore my Balt and don't want to lose her. Yes, even with all these issues I've been fighting with since November. :-) I've lucked out with my mechanic and have paid less than 700 bucks for new injectors, new plugs (twice), new throttle body, new fuel filter, new coil pack, AND new tires (hubby gets a discount on GM parts since he has a body shop, and the mechanic is charging me super great labor rates, plus not charging a cent when I go in every few weeks and have him read/clear codes), so I know that this isn't just something that my wrench is trying to screw me on. I understand that a little miss is considered "normal", but a miss that shakes my entire car at a stop and throws a P0300 every couple of weeks?? Yeah, that's not anywhere NEAR "normal".