2003 GAGT1 misfire

[klokworx]

hey everyone, im new here but i was on GAOC for a while.

i got an '03 gagt1 with a cylinder 1 misfire code and a p0300 code in the DLC history.

it runs fine when i start it up, runs good when i start driving it but about 5 minutes into driving it my SES light comes on, my trac off light comes on, i lose acceleration even when i kick it down a gear. i have no heat in the cab at idle, ive bled the system. i recently got a full cooling system tune up including new intake gaskets. its got new plugs and wires. i did a compression test, its equal all around, no abnormal drops or spikes in psi. sitting around 150 ±5 psi. im not losing coolant and i replaced the reservoir cap.

im narrowing it down to 3 things and i hope someone can chime in if im on the right path or if im wrong:

1. bad CAT (smell of rotten eggs from exhaust)
2. bad ECM
3. bad 1/4 coil pack

 

[msmith1956]

Welcome aboard Klokworx, it's good to see you here. I'd look at the coil pack first.
You can find instructions on the best way to do it here: http://easyautodiagnostics.com/

 

[klokworx]

excellent, thanks a bunch. ill check it out tonight when i got more time. im hoping thats all it is. but would it be the cause of no heat at idle as well?

 

[msmith1956]

No, I kinda doubt it would effect the no heat issue. I see you said you've bled the system... did you have the heat on when you bled it?

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[klokworx]

Heat was off at first them turned it on. The coolant sucked way down, so added coolant and trebled it.

On the coil note, do these MSD coils work on these cars or no? http://www.jcwhitney.com/msd-ignition-coil/p2005121.jcwx?filterid=d1831y2003g459

I know these cars are picky on what's used

 

[klokworx]

It was off at first, then I started it up and turned the heat on. Turned the car off, topped up the coolant and bled again.

On the coil note. Do the MSD coils from jcwhitney work on our cars?

 

[CatSkinner]

MSD makes ignition coils for your car, but I can't guarantee JC carries them.

 

[klokworx]

just from what i seen for a custom fit they had them, just wondering if they worked better than the regular coils.


update: so i switched coil packs 3/6 with the 1/4. plugged it back in. test drove it after i cleared the code. i ran it hard to try to get that p0301 code to pop up but it wouldnt pop up. my temperature gauge redlined for a few seconds then dropped back down to normal, so i took it on the highway and redlined it trying once again to pop that code. again my temp gauge redlined, and my trac off light came on. i got home left it running, popped the hood and my coolant was pissing out the overflow once again. everything that was happening when the code was there but this time no code. im stumped here

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[melsg5]

have you flushed your cooling system and replaced the thermostat?

 

[klokworx]

Yeah the thermostat was put in in the spring. I had the cooling system flushed with the intake procedure

 

[melsg5]

You either have have air in the system or a bad thermostat. You checked the front of the radiator to make sure its not blocked by leaves?

 

[msmith1956]

If your thermostat is good, and there is no air in the system, it's starting to sound like it could be a head gasket problem.

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[Zimgxp]

Does the overflow have bubbles in it when it is running? You need to have the coolant checked for hydrocarbons.

 

[klokworx]

well as of right now im at a stand still with it. i bought my buddys saturn, put a new starter in it. only cost was the starter. my GA is gonna be sitting till spring or until we move to a place with a garage. which is really depressing, i hate seeing it just sitting there. but thats the way it goes. i have it up for sale, if it sells it sells, it it doesnt it doesnt.

 

[klokworx]

heres the update. since i sold it i asked the guy to let me know whats going on when he opened it up. headgasket was gone