19z28camaro02

Its missfiring, i think its on the left bank(driver's side), sprayed the plugs, nada, cleaned the EGR valve, nada. Tomorrow I'm gunna try new plug wires, any other hints?

19z28camaro02

Please Help!!!

MeanGreen97Z

Give us a little more info.

Is this at low/high rpms?
Occurs at idle?
Change anything on the car before it started doing this?
Has it rained or did you wash the engine bay?
How do the old plugs look?
See any wires arcing at night?
Is this when the motor is cold or warm? Or at all times?
What exactly makes you think its a misfire and not a fuel problem?

19z28camaro02

Its throwing the P0300 code at me which is missfire.
occurs all the time
nothing changed
it was raining the day it started, BUT, it did it after i had shut the car off and started to missfire when i turned it back on

MeanGreen97Z

Sounds like something got wet and PO300 is a random misfire code. Not specific to any one cylinder. Sounds like one of your ignition components got soaked. How long has this been happening?

19z28camaro02

since thursday, i checked the boots and didnt see anything, i checked the EGR valve, and tomorrow i'm gunna try to swap a few of the wires with some new ones to see if i can figure it out to wires or the opti. You thinking opti?

MeanGreen97Z

Im thinking opti... you bet man. After a rain and the car starts acting weird you can almost guarantee its the opti. How many miles on this opti? Yours is vented but that doesn't make it safe from liquids. Try swapping the plugs and the wires and see what happens. It's cheaper than a new opti.

19z28camaro02

yea, wires are definately cheaper, i've got 80 or 81k on the car, original opti. But one thing that almost doesnt make me think opti is that it only did it after i got back into the car and started it after it sat for 5-10 minutes, its not like i drove through a puddle and 5 seconds later the light went on.

MeanGreen97Z

I would start by pulling the plugs for sure. Check wires and wiring.

ajlew9428

does it miss when you first start the car when in closed loop? Mine did terribly, and I just found out my 02 sensor wires were shot. Fixed them, now my car runs good again

19z28camaro02

I pulled the spark plug on the #1 cylinder and it looked a little "sooty". changed it, cleaned the EGR, not the problem

ajlew9428

like I said above. if its the left bank, and your car isnt batch fire, check the 02s. Run the o2 tables see what you get. My car was missing terribly, and I found my o2 wire was shorted. I thought as well as everyone else that it was my opti. Opti is like god in this forum. if something we dont understand is wrong, we just say the opti did it