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check engine light flashes

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Old 01-07-2009, 08:04 PM
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Default check engine light flashes

i have a 01 gmc jimmy and when you put the pedal to the floor about after 70mph the check engine light will flash. I have pulled the code and got bank 1 and bank 2 to lean could this be my o2 sesnors?
 
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Old 01-07-2009, 08:06 PM
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Default RE: check engine light flashes

how many miles the truck have and wats the exact code
 
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Old 01-07-2009, 08:14 PM
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Default RE: check engine light flashes

p0171 and p0174 and almost 92,000 miles
 
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Old 01-07-2009, 08:25 PM
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Default RE: check engine light flashes

Description of DTC P0171 or P0174
Circuit Description
The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop the PCM determines fuel delivery based on sensor signals, without oxygen sensor input. During Closed Loop, the oxygen sensor inputs are added and used by the PCM to calculate short and long term fuel trim, fuel delivery adjustments. If the oxygen sensors indicate a lean condition, fuel trim values will be above 0percent. If the oxygen sensors indicate a rich condition, fuel trim values will be below 0percent. Short term fuel trim values change rapidly in response to the HO2S voltage signals. Long term fuel trim makes coarse adjustments in order to maintain air/fuel ratio of 14.7:1. If the PCM detects an excessively lean condition, this diagnostic trouble code (DTC) will set.
Conditions for Running the DTC[*]DTCsP0101, P0103, P0108, P0135, P0137, P0141, P0200, P0300, P0410, P0420, P0430, P0440, P0442, P0443, P0446, P0449, P0506, P0507 or P1441 are not set.[*]The engine coolant temperature (ECT) is between 75-115°C (167-239°F).[*]The intake air temperature (IAT) is between -20 to +90°C (4-194°F).[*]The manifold absolute pressure (MAP) is between 26-90kPa (3.7-13psi).[*]The vehicle speed is less than 137km/h (85mph).[*]The engine speed is between 400-3,000RPM.[*]The barometric pressure (BARO) is more than 74kPa (10.7psi).[*]The mass air flow (MAF) is between 5-90g/s.[*]The fuel level is more than 10percent.[*]The throttle position (TP) is less than 90percent.
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Conditions for Setting the DTC[*]The average long term fuel trim cell value is above 23percent.[*]All of the above conditions are present for 6seconds.
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Action Taken When the DTC Sets[*]The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.[*]The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
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Conditions for Clearing the MIL/DTC[*]The control module turns OFF the malfunction indicator lamp (MIL) after 3consecutive ignition cycles that the diagnostic runs and does not fail.[*]A current DTC, Last Test Failed, clears when the diagnostic runs and passes.[*]A history DTC clears after 40consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
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Diagnostic Aids[*]The system will go lean if an injector is not suppling enough fuel.[*]A lean condition could be present during high fuel demand.
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Some things to try:[*]Check the HO2S for proper installation.[*]Check to ensure electrical connectors and wires are secure and not contacting the exhaust system.[*]Vacuum hoses for splits, kinks, and proper connections[*]Check for missing, loose, or leaking exhaust components, forward of the HO2S.[*]Check for vacuum leaks at the intake manifold, throttle body, and injector O-rings.[*]Check air induction system and air intake ducts for leaks.[*]Check the secondary air injection (AIR) system for leaks, improper air delivery, shut off valve not closing[*]Check crankcase ventilation system for leaks.[*]Make sure gas tank had enough gas in it and that the fuel is not contaiminated.[*]Aworn cam, worn intake or exhaust valves could also be at fault


Also try cleaning the MAF sensor there is a good DIY in the DIY section just search for it. Also another you could try is to clean the O2 senors you coulduse brake cleaner to clean them.
 
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