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Pontiac Repair/1999 pontiac montana back firing


I am having problems with my montana. It has started hesitating and back firing at speeds between 45 to 65 mph. If I stay steady at about 70-75 it runs smoothly but when I slow down it starts up. I am thinking mass air flow sensor but I cleaned and still acting up.

Hi Priscilla:

is it running rough and misfiring? if so that could be something as simple as a bad sark plug wire. does it do it more when it's damp out/raining or on a cold damp Am? A MAF can call cause a hesitiation for sure but not just in a narrow speed it will do it all the time. has the service engine soon lamp come on? if so stop by one of the big box auto parts stores and have it scanned for codes and see what is stored. that will leave a thumb print to a potential problem.. Good luck :-)

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Todd Puccio


General auto repair,electrical issues,driveability issues,anti-lock brakes,SIR systems,HVAC,engine performance,Gm specific. I have worked at my current dealership since the 1990 model year anything much older than that I have limited exposure to. I do not have very much transmission experience so those question you may want to ask of another expert. When you send me a question let me know the exact make/model/engine and year for the car or suv you have it makes it easier to answer the questions that way. If your happy with the answer I gave you please feel free to Donate. This is a free service to you and I am not compensated at all by this web site. I have 22 years of experience to share with you and my knowledge wasn't free to me. I had to pay for my education.


Experience in the area: I have been a technician in GM dealerships for over 22 years and I am a ASE master technician. I work at a Buick and GMC truck store Previously I worked at a Pontiac GMC store for 18 years. I Served a a lead technician when dealership was on a team system. I just recently moved to a Buick,Hummer,Saab Store when my franchise was purchased by this dealership. Organizations: ASE master technician


Education/Credentials:High school diploma,2 year vocational school degree 2 year college degree. Associates degree in applied sciences (auto technology)Awards and Honors: GMC master technician

Awards and Honors
Master GMC truck technician Master ASE technician in 9 categories

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