2006 H2 Limited Edition Power Issues - Re-Gearing??

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2006 H2 Limited Edition Power Issues - Re-Gearing??

Postby 2006H2LE » Tue Jul 12, 2016 12:40 pm

2006 Hummer H2 Limited Edition
Late 2006 Hummer H2
Fusion Orange
Tires: 37x22x13.50

• 2nd Owner
• Running 93 Octane otherwise terrible power and acceleration???
(Don’t know if previous owner had a supercharger or reprogramed the ECU. GM Dealer tried to re-flash ECU 2 Times will not accept re-flash)

• Constant Knock Sensor Codes (P0032) Knock Sensor 2 Circuit Low Bank 2
(Replaced both Knock Sensors and Installed New Harness Twice still same Problem)

• Transmission Temperature (200*) during normal operation

• Engine Temperature (200*) during normal operation
(Replaced Radiator & Thermostat last week due to hairline crack in Radiator still running at same temperature)

• Feels like the transmission does not downshift when braking to a stop…Is this normal?

• When accelerating from Stop no power until 3500 RPM

• Cannot maintain 4th Gear over 75mph will downshift to 3rd Gear and remain until pedal is released.

• 3rd Gear power is almost non existent when on highway to pass another vehicle

• Once in overdrive 4th Gear slightest acceleration of throttle will cause immediate downshift.

• Fuel Economy is horrible 7.5 mpg ( How can this be increased?

• Water Leaks into Cab of vehicle in 3 Locations Drivers Side & Passenger Side Front near A-Pillars headliner corners are saturated in heavy rains and also rear Passenger Side in trunk notice water in storage cutout above wheel well
(Have inspected Marker Lights for possible leaks and found them all to be tight and ran a bead of Urethane around the lights to ensure no leaks are possible however still have the water issue)

Thinking of Re-Gearing the truck… anyone have any suggestions of what to run?
Truck is used On-Road 80% of the time for Highway driving my normal running speeds are
80MPH to 90MPH

Regarding the vehicles running issues acceleration power knock sensor codes I have heard the following from GM MasterTechs and Independent Mechanics.,,,,

Possible Torque Converter Issue…..
Possible Timing Chain Issue….
Possible ECU Programing for SuperCharger that has since been Removed….

I am at a loss here… I love this Truck but need to fix the Power concerns.
It truly feels like the truck is bogging down almost as if there is a restriction. I even went so far to remove the exhaust from the back side of the headers to see if it was an exhaust restriction… only difference was the truck sounded like a car at Daytona 500 lol …. Lots of noise and still same power issues and bogging down So I ruled out exhaust restriction as a culprit.

The spedo is off by about 5-7mph due to the larger wheel and tire size
My Fuel economy is absolutely horrible which makes sense since the vehicle is always running in 3rd gear above 3500 RPM.

Any help or recommendations from others that have experienced similar issues is greatly appreciated.
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Vehicle: 2006 H2 Limited Edition

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