My car started misfiring while i was on the road. PO300 code came on my reader i checked it out and then let the car set overnite. The next day checked it and it was gone my car ran fine, hasnt poped up since. Why would this occur?

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07 GP(base)ol' whitey, Headers/3"DP, CAI, 180*stat, HV3. Im the HotRodder with the HotRod!

I just experienced this myself. P0300 came up, then it would be fine the next day, or even a few hours later. I let it go for about 3 weeks, but by that time, it was constant. I had a spark plug that was going bad. Replaced all 6... car runs like a champ now. Also, I get around 350-400 miles to the tank... I only got 160 miles in my last tank when It was misfiring. Change your plugs. It should cure the problem.

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---2005 GP GT---

Yea plugs wires, maybe an induction and injection flush would help. Have a look at your EGR to see if it may be malfunctioning and dumping exhaust into your intake at the wrong times as this would cause poor idle and driveability, however typically a malfunctioning EGR would throw a different code but you never know.

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Fast.Loud.Shiny

Im goin to get iridium spark plugs for this tune-up and 8.5mm plug wires.

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07 GP(base)ol' whitey, Headers/3"DP, CAI, 180*stat, HV3. Im the HotRodder with the HotRod!

after i changed my plugs n wires i started getting 400+ a tank, so deff a good idea

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04 GP GT
K&N CAI, SLP Exhaust, 180 TSTAT,GMPP STB's,Tints,Weather Tech Rain Guards,Front/Rear Bumper Inserts and Rocker Panel Decals from Reflective Concepts, Windshield Banner,Reverse Bar Overlay, and Door Sills from H.O.G.,Custom Emblem from Emblem Pros,Kenwood 6X9's

Sweet.

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07 GP(base)ol' whitey, Headers/3"DP, CAI, 180*stat, HV3. Im the HotRodder with the HotRod!

Could be your ICM as well. I have the same issue because of a flaky ICM.

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