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I have a 08 GXP 3.6L auto w 110k. The car has recently developed a part throttle stutter, hesitation at cruising speed particularly when going uphill. It will continue doing this unless the go pedal is depressed to accelerate regardless of whether it downshifts or not. Code P0303 (cylinder 3 misfire) code was stored. I erased it and drove it today. It still does it however the CEL has not come back on. I've also had the T/C light come on and the CEL flash for several seconds but not stay on. This may be unrelated as it occurs under hard acceleration but it doesn't seem that the drive wheels are losing traction. Ideas or suggestions?
 

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A flashing CEL is an indication of a misfire. The T/C light is also likely from the misfire.
Misfire could be spark plugs or ignition coil. IIRC the coils on the 3.6 are Coil per plug. So it's possible one ignition coil has failed. You can try swapping cylinder 3 coil with cylinder 1 and see if the misfire code follows it. If so then you know for sure it's the coil.
At 110k you're probably due for a tune-up if you haven't had one yet.

I would also check the simple stuff, air-filter. Clean the MAF sensor, clean the throttle body.
 

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Thanks Cruising G6. I recently bought it for a daily and figured as much regarding the tune up. I'll swap the coils and clean the MAF and Throttle body as well. Thanks again!
 

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I swapped the #3 coil with another and so far no code! I still feel an occasional miss but less severe and frequent. My assumption is that the coil is weak and over time has degraded the #3 plug. I ordered new plugs and a coil. Thanks again Cruising G6!
 

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Anytime! The coil itself could have some corrosion either on the connector side or the spark plug side, moving it around could have cleaned some of that corrosion off.
During your tune up make sure everything is nice and clean and add some dielectric grease to keep things from seizing and corroding.
 

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Did the coil replacements fix the problem? I posted this same question today, as mine is doing the same thing. I'm taking it to the mechanic on Tuesday and had the codes checked today, but there were multiple ones including the misfire and the ABS which he said would be related to the TC light coming on.
 

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Did the coil replacements fix the problem? I posted this same question today, as mine is doing the same thing. I'm taking it to the mechanic on Tuesday and had the codes checked today, but there were multiple ones including the misfire and the ABS which he said would be related to the TC light coming on.
If the ABS system loses the signal to one of the wheel speed sensors, it'll also disable the traction control as the system can't tell how fast each wheel is spinning.
 

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Yes the problem is gone and the car runs great. The plug electrodes were pretty worn. I'm not sure if the coil was bad but I changed it anyway. The CEL never reappeared after I moved the suspect coil to another cylinder. Thanks again Cruisin G6! Good luck with your car Ssamuels!
 

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I recently bought a 08' G6 3.5L and it was very well maintained and taken care of. It has 128,000 on it but was owned by an elderly lady from 30,000 on and taken to her personal mechanic for all up keep and repair. It has had all recalls addressed as well. She didn't drive it very far or fast either. I noticed that on the highway uphill it was stutter slightly until i push on the gas slightly harder. It runs great and drives beautifully this is the only issue i am having. No light on dash and no jump in rpms when it does it. It also shifts just fine. Was curious if anyone could point me into the right direction to get it fixed. I know i have a good car and want to get the most out of it. I would appreciate any and all input thanks.
 

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I recently bought a 08' G6 3.5L and it was very well maintained and taken care of. It has 128,000 on it but was owned by an elderly lady from 30,000 on and taken to her personal mechanic for all up keep and repair. It has had all recalls addressed as well. She didn't drive it very far or fast either. I noticed that on the highway uphill it was stutter slightly until i push on the gas slightly harder. It runs great and drives beautifully this is the only issue i am having. No light on dash and no jump in rpms when it does it. It also shifts just fine. Was curious if anyone could point me into the right direction to get it fixed. I know i have a good car and want to get the most out of it. I would appreciate any and all input thanks.
To my mind your best bet is to have the car scanned for diagnostic trouble codes. Auto stores will often do this for free or you can buy scanners pretty cheap. The scanner lets you see what the engine management system is reading and if it is sensing problems. Some codes will remain "pending" if they do not happen each trip and will not illuminate the dash CEL. Other diagnostic data may also be available to help track down the problem.
 
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