Question about 1999 GMC Yukon Denali

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99 gmc no power when passing or climbing

99 gmc 4x4, truck is mechanicly taken care of, problem is if i trump on the gas the truck will hesitate, motor sounds muffled, pinging noise like bad gas, shifting is held back. If I ease into to it, to go faster, it works fine. Great accelleration, smooth, shifts nice. I have changed: plugs, wires, TPS, MAP, MASS, intake gasket, fuel filter, air filter, had the injectors cleaned and tested, fuel pressure is good, changed all O2 sensors. What could this be???? 1999 GMC DENALI-when I shift into passing gear it kicks down but it won't "power through" the gear and shift-thought catalytic converters were bad-replaced y pipe and 2 or the 4 02 sensors still no good. No power on take off towing or hills

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  • Anonymous Mar 28, 2014

    Will replacing the throttle position sensor and the MAP sensor lower my hydrocarbons


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It could be the cat. it sounds like this could be your problem

Posted on Feb 07, 2009

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SOURCE: 99 gmc no power when passing or climbing

It could be electric fuel pump stall. The pump isn't pumping fuel fast enough. This model may have a inline fuel filter before the fuel pump as well that might need replacing.

Posted on Dec 02, 2008

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99 gmc no power when passing or climbing

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