SES Light

[04crewvt]

I just pulled code 172 and 175 on my truck both banks showing rich condition, any ideas on what may need to be checked?

[killian96ss]

I just pulled code 172 and 175 on my truck both banks showing rich condition, any ideas on what may need to be checked?

P0172 & P0175

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 0 percent . If the oxygen sensors indicate a rich condition, fuel trim values will be below 0 percent . 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. The fuel trim diagnostic will conduct a test to determine if a rich failure actually exists or if excessive vapor from the Evaporative Emission (EVAP) canister is causing a rich condition. If the PCM detects an excessively rich condition, this Diagnostic Trouble Code (DTC) will set. If the PCM detects excessive vapor then a pass is logged.

CONDITIONS FOR RUNNING THE DTC

DTCs P0101, 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 26-90 kPa (3.7-13 psi).
The vehicle speed is less than 137 km/h (85 mph).
The engine speed is between 400-3,000 RPM.
The Barometric Pressure (BARO) is more than 74 kPa (10.7 psi).
The Mass Airflow (MAF) is between 5-90 g/s.
The fuel level is more than 10 percent .
The Throttle Position (TP) is less than 90 percent .

CONDITIONS FOR SETTING THE DTC

The average long term fuel trim value is below 13 percent
All of the above conditions are present for 40 seconds.

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.

CONDITIONS FOR CLEARING THE MIL/DTC

The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive 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 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS

Fuel contamination, such as water and alcohol will effect fuel trim.
A malfunctioning mass air flow sensor can cause a rich condition and set this DTC.
An EVAP canister that is saturated will cause a rich condition.
Fuel in the vacuum line to the fuel pressure regulator indicates a leaking regulator.
A worn cam, worn intake or exhaust valves or other engine mechanical failure may be at fault.

This is probably more info than you need, but it should at least point you in the right direction.

Steve

[04crewvt]

Well I was low on gas and had just filled up when the code set and it was 2nd day of heavy rain. I guess I could have gotten some cr** from the bottom of the fuel pump/tank in the line or some water from the high relative humidity. I will see if it comes back and will pick up some MAF cleaner I haven't cleaned that since I got the truck. With ony 25k on it I would hazard a guess that the mechanical side is still fine.

[killian96ss]

I would go ahead and clean the MAF anyway since it is such an important sensor. I would also recommend adding one bottle of fuel injector cleaner and one bottle of water remover just to be sure you don't have water in the system contaminating everything.

Steve