1999 Pontiac Sunfire PO200 & PO300 codes

1999 PONTIAC SUNFIRE
160,000 MILES
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FREMONT
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looked at almost everything that relates to these codes and i can't find anything wrong but i got a bad miss. what is the chance i got a bad PCM? GOOD wires,plugs, coils, ICM, New crank sensor, Cam Senor ? did unplug and did get code , so i believe it is good? Injectors are good, i did a noid check on all 4 and that looked good. high speed runs good, low speeds and idle a real bad miss?
Jul 13, 2013 at 1:36 PM
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JACOBANDNICKOLAS
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Are you able to narrow it down to which cylinder is missing?
Jul 13, 2013 at 2:01 PM
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FREMONT
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no i am not able to, it is so random. the spark plugs #3 & #4 were blackened(rich) #3 was more then #4. #1 & #2 looked good.i also hooked up my test light to see witch cylinder is missing and they all are. the car starts up with no problem. i tried a leak down by pulling sprk plug wires and it so hard to see a difference? i thought a about a compression test? the car has been running fine,so something went out just like that?
Jul 14, 2013 at 5:01 AM
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FREMONT
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One other thing. I need to make up a fitting so i can check the fuel preasure. Do know if they sell that fitting/tool to hook up my fuel gauge tester? i will look on line for one. this is one thing i havent checked. i can hear it run when i turn the key i just don't know the PSI?
Jul 14, 2013 at 5:06 AM
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JACOBANDNICKOLAS
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I'm not sure what type you have, but you should be able to find an adapter.
Jul 14, 2013 at 1:16 PM
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FREMONT
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Fuel PSI/regulator is good. So what do you think?
Jul 15, 2013 at 3:21 AM
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JACOBANDNICKOLAS
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  • 110,240 POSTS
The ignition has new parts, the fuel pressure is correct and we have a misfire. Have you checked engine compression?
Jul 15, 2013 at 1:39 PM
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