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random misfire confusion

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Old Jan 15, 2011 | 01:37 PM
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Default random misfire confusion

this morning i started my car (been a couple days) it ran at a little bit of a higher rpm for about 2 mins while it was doing so i thought i heard it misfire just once, well i get in the car and see the SES light is on, drive up to advanced auto for a scanner read and it says multiple random misfire, but i still have not felt or heard another miss out of it, i drove it for about 20 mins after the scanner and let it run in the driveway just listening for a miss for about 15 mins i still dont hear one, is it possible it only missed that one time?? im gonna wait til its cool and pul the plugs and wires and see if any of them are looking rough this happen to anybody else?
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Old Jan 16, 2011 | 01:36 AM
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Your best bet at this point is to clear the code and see if it comes back. Multiple random misfire is more difficult to diagnose than any once cylinder, and I wouldn't personally worry about it as it may be a one-time thing (eg bad gas). Did you get a slow oxygen sensor code too by any chance? If you did, you may have an exhaust leak..
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Old Jan 16, 2011 | 11:02 AM
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i had it reset shortly after i posted this yesterday and the light hasnt come back, no 02 code but i know for sure i have a slight exhaust leak too,waitin for tuesday to get it welded up, thanks man
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Old Jan 17, 2011 | 08:31 AM
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That's probably a good thing The idea is that the exhaust leak throws off the oxygen sensor's reading, which subsequently results in an improper correction in fueling. This can cause missfire of course.
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