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01 Catera getting P0300 code

14K views 58 replies 9 participants last post by  retho78 
#1 ·
Hi,

My in-laws car had a P0300 code come up (random misfire detected). Where do I start? Could it be the plugs, coil pack or oil leak going into the plugs?


Thanks.
 
#4 ·
That's the only code that showed up on my scanner. The car has new timing belt, water pump and serpentine belt. These were replaced early this year. I don't think there is any vibration, but will check and see what exactly is going on. I think it may be the valve coer gasket leaking oil and going into the plugs.
 
#7 ·
The car has about 135K and the plugs were changed early last year. I'm think it could be the coil pack or the plug wires, because once I started it the other the day, the car had a slight shake and when I accelerate it, the car would run fine and then it was okay. So far it is running fine, but will keep an eye.
 
#17 ·
Just an update! After few months without any problem (didn't replace anything), the check engine light came on two weeks ago , scanned it and it showed cylinder 6 misfire (don't remember the code). Turned the check engine light off and drove it for another week without any problems, then the check engine light came on again yesterday after driving it for few minutes. This time the check engine light flashed for few seconds and the car slowed down, would not accelerate enough, could only drive it like 20 miles an hour and brought it back home. Could it be that the ignition coil pack is bad?


Thanks.
 
#20 ·
I was just looking online for the ignition coil and I see some brands selling two kinds (same side), one with a white connector end and one with a black connector end. Does anyone what the difference are for these coils? I know that the prices are different!!!


Thanks
 
#23 ·
Thanks, I also got a great deal on the coil. I ordered it online from Advance auto parts and used coupon code, then picked it up from the store. The one I got was the BWD brand, and it is made by Bosch. It looks exactly like the orginal one in the car.
 
#24 ·
The car is having the random misfire issue again.

I replaced the passenger side coil with new plugs a month ago because it was running rough with the random misfire (same code P0300) and it ran well until yesterday it started to do the same thing. I scanned this evening and it showed the same code P0300. Also, one of the O2 sensor has been bad for a while and has the code for that. Could that be the problem for the misfire or could it be something else?

Thanks.
 
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