DMPesso

I hope someone knows what this could be because it killed my night, I have a 99 GS3 with about 150k miles and everything was fine but i decided to change the spark plugs and ignition wires, i used ngk iridiums and duralast wires because thats the only ones they had it was from autozone. My mechanic changed them as well as cleaning the throttle body. It was running perfect for 20 mins and then it started bogging out on idle and acting weird, then the check engine light started blinking and i got the codes read, it was: PZ0303 and PZ300 - Cylinder 3 misfire. Does anyone know what this could be. Also I had my girl press the gas while I looked under the hood and i heard like a ticking/sparking noise coming from the engine area. I don't know if that means anything. Thanks CL

BCP43002

It could be any of the following:

Open or short in engine wire
Connector connection
Vacuum hose connection
Ignition system
Injector
Fuel pressure
Mass air flow meter
Engine coolant temp. sensor
Compression pressure
Valve clearance
Valve timing
ECM

I would check to make sure the spark plug wires are properly connected first.

tom steele

either injector or coil pack more then likely the coil

DMPesso

And also when he pulled the plugs they all had alot of oil on them and he said the valve cover gasket are leaking and another gasket that connects the throttle body to the intake manifold has a rip in it. But the car ran fine before the plug change. What could the plug change have done?

lexybaby77

It could be alot of things. It could be something really small. Make a visual inspection of the engine and see for anything loose or disconnected (plug wires, vacuum hose etc..) If your valve cover gasket is leaking then there will be oil in your spark plugs. Might as well change the Valve cover gaskets and start from scratch. Go to Napa Auto parts (if you have in your area) or dealer for the plug / plug wires, NGK and Denso. More expensive but makes alot of difference in the long run. Hire an experienced mechanic to do it for you. Not worth the hassle IMHO.

sam430

iTrader: (10)

quick test. swap coil 3 with another one...if the misfirr follows the coil, then its the coil.

DMPesso

My mechanic took it apart and cleaned cylinder 3 because there was more oil in 3 then the other ones and put it back together. After driving for 15 minutes it started up again. Then I was driving for about 30 minutes and the VSC and VSC off light came on and stayed on. the CEL would blink about 8 or 9 times and then stay on and then blink and go off. He said that when he was taking everything apart since the plugs were never changed and the car is so old the black tape and black housings protecting certain wires fell apart and he didnt use any tape to cover it so hes thinking the sparking was coming from a wire touching something metal under the manifold and it could be grounding out the 3rd cylinder. But now the VSC lights? any opinions would be loved at this point :-(

jasonb75

iTrader: (1)

I know exactly what your problem probably is. Search my posts for a write up on it.

jasonb75

iTrader: (1)

Well, I will go ahead and post the link for you. Mine would run great when cold, then start misfiring. I had the exact same symptoms, and the same lights on.

Here is the link for you.
https://www.clublexus.com/forums/gs-...onnectors.html

DMPesso

Thanks so much but I feel like my problem may be different since it only happened after the plugs were changed. So something had to go wrong then. You changed the coil pack itself or just the connector? I don't understand how changing the plugs and ignition wires could cause this. Enlighten me please

jasonb75

iTrader: (1)

Mine was perfect before doing plugs and wires on my car also. When I took the connector off the coil, it basically disintegrated in my hands. You have to take that connector off the coil to remove the coils to get to the plugs. The plastic gets brittle over time because of the heat and age. If you never touch it, it stays intact. Once you go to remove them to do the plugs, they fall apart.

I just changed the connectors, I still have the original coils.

FrankT

Replace #3 wire with the old one...

Autozone wires may be grounding out.

I would only use OEM TOYOTA plug wires...or better.

I believe if it was a coil you would have 2 misfires...your mechanic should already know this.

CoilPack connectors need to be replaced. And thanks Jason, for this thread, DIY GS300 coil pack connectors

DMPesso

Thanks for everyones help but for everyones future reference don't ever buy PIECE OF **** duralast ignition wires from autozone because I got NGK ones from an independent auto parts store cuz autozone only has duralast and they snapped all the way on unlike the duralast ones and so far the problem is gone. So I guess it was the oil from the plugs seeping into the ignition wire since it didn't sit on as well as the original ones. I learned a hard mistake, always buy dealer parts when it comes to stuff like this. Thanks everyone though