2002 Grand prix Hesitates On Acceleration

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2002 Grand prix Hesitates On Acceleration

Unread post by ArtJohnson » Wed Oct 31, 2012 7:51 pm

hesitates at certain spots in acceleration. went to auto zone and was told Mass air flow / O2 sensor bank 1 and bank 2. possibly cat converter. all parts pricey. they suggested taking to dealer and dealer could pin point problem. is this correct or will they just start changing parts. any ideas on where to start 1st

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Re: 2002 Grand prix Hesitates On Acceleration

Unread post by ProTech » Thu Nov 01, 2012 6:09 pm

The dealership can definitely do a better job of determining what you need to fix your vehicle, but there is a charge to check it out. If you end up doing the repairs at the dealer, that charge is included in the total repair cost. You sure don't want to just start guessing at expensive parts. I've seen many times, a mis-diagnosed problem end up costing way more than it should due to unnecessary parts replacement. If you do need a MAF sensor, and either of the O2 sensors, I would highly recommend using GM parts. If you end up needing a catalytic converter, you might opt to have it replaced at a muffler shop, as it would be extremely cheaper. Just make sure they install one that is sufficient for your vehicle. Any and all of those can cause a hesitation, so you might want to get it checked out at the dealer to be sure.
GM Dealer Technician For 18+ Years
In the automotive industry for 20+


Misfire on acelleration

Unread post by Mike1977 » Sun Aug 16, 2020 12:04 pm

So I have a 2006 Pontiac Grand Prix 3.8l .she has new cat and exuhust new o2sensors new plugs and wires and a new icm ..but she is still misfiring when I accelerate. The egr is clean and the pcv valve is clean also ..I also checked each coil pack for spark while running ..can a coil pack still b bad ?I had a misfire code for cyl 5 could that coil pack b bad ?

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Re: Misfire on acelleration

Unread post by carriedi » Tue Aug 18, 2020 4:43 am

if you question the coil, change it to another cylinder. See if the misfire follows the coil to the new cylinder. If it does then it's the coil. If it doesn't try switching the fuel injector to a different cylinder. If the miss follows the injector then... replace injector. If the misfire stays on #5 after switching the coil and the injector then you have to look at the injector driver or coil driver. After that you're looking at something mechanical with the engine. Do a leak down test on the cylinders on that side of the engine.

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