Fuel & Air Metering Trouble Codes: List & Fixes

P0174 Powertrain The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction… Moderate P0101 Powertrain The MAF sensor's airflow reading doesn't match what the engine computer expects… Low P0113 Powertrain The intake air temperature signal is stuck at maximum voltage, which usually means an open… Low P0135 Powertrain The heater inside the upstream oxygen sensor on bank 1 isn't working or its circuit is faulty. Low P0171 Powertrain The engine computer is adding the maximum extra fuel it's allowed on bank 1 and still sees… Moderate P0172 Powertrain The engine computer is pulling as much fuel as it's allowed on bank 1 and the mixture is still… Moderate

P0266 Powertrain The engine computer can't even out cylinder 2 with fuel corrections; its balance rate is past… Moderate P0269 Powertrain Cylinder 3 isn't pulling its weight, or is pulling too hard, and the fuel correction for it… Moderate P0272 Powertrain The ECU can't balance cylinder 4 against the rest anymore; its fuel correction is outside… Moderate P0275 Powertrain The fuel correction for cylinder 5 is past its limit. Only engines with five or more cylinders… Moderate P0299 Powertrain The turbo or supercharger isn't building the boost pressure the engine computer is asking for. Moderate P052E Powertrain The crankcase ventilation regulator isn't controlling crankcase pressure properly – often… Moderate P0597 Powertrain The electrically heated thermostat's heater circuit is open, so the ECU can't open it early… Low P1101 Chevrolet · Powertrain GM's engine computer found that measured airflow doesn't agree with what it expects. Low P1128 Jeep · Powertrain Your Jeep's PCM never switched bank 1 from preset fueling to O2-sensor feedback after… Low P1128 Volkswagen · Powertrain VW's part-load fuel adaptation has maxed out adding fuel on bank 1 – the engine runs lean as… Moderate P1129 Jeep · Powertrain The PCM couldn't switch bank 2 of your Jeep's V6 or V8 into oxygen-sensor-controlled fueling… Low P1131 Ford · Powertrain Ford's front O2 sensor on bank 1 stays lean even after the PCM has added all the fuel it… Low P1132 Ford · Powertrain Ford's front O2 sensor on bank 1 keeps reading rich even though the PCM has pulled out as much… Low P1133 Chevrolet · Powertrain The front oxygen sensor on bank 1 isn't flipping between rich and lean often enough during GM's… Low P1134 Chevrolet · Powertrain Bank 1's front O2 sensor reacts much faster in one direction (rich or lean) than the other. Low P1135 Toyota · Powertrain The heater inside Toyota's upstream air/fuel ratio sensor is drawing too much or too little… Low P1136 Volkswagen · Powertrain At idle the VW computer is adding the maximum fixed amount of fuel on bank 1 – a classic vacuum… Low P1137 Volkswagen · Powertrain At idle the VW computer is pulling out as much fuel as it's allowed on bank 1 and the mix… Low P1151 Ford · Powertrain On a Ford V6 or V8, the front O2 sensor on the bank 2 side stays lean and never switches back… Low P1152 Ford · Powertrain On a Ford V6 or V8, the bank 2 front O2 sensor sticks on rich even after the PCM leaned that… Low P1153 Chevrolet · Powertrain The front O2 sensor on the passenger-side bank of a Chevy V6/V8 isn't cycling rich-lean often… Low P1154 Chevrolet · Powertrain On a Chevy V6/V8, the bank 2 front O2 sensor rises and falls at clearly different speeds. Low P1155 Toyota · Powertrain The heater in the front-bank air/fuel ratio sensor of a Toyota V6 or V8 is out of its current… Low P1157 Honda · Powertrain The signal lines of Honda's upstream air/fuel ratio sensor read too high, usually an open… Low P1166 Honda · Powertrain The circuit that powers the heater in Honda's upstream A/F sensor is open, shorted or unpowered. Low P1167 Honda · Powertrain The upstream A/F sensor heater is powered but isn't drawing the current or heating the sensor… Low P1233 Ford · Powertrain The Ford PCM lost the status signal from the fuel pump driver module, so fuel pump control… Moderate P1259 Honda · Powertrain The PCM saw the VTEC solenoid or VTEC oil pressure switch misbehave on an older Honda VTEC… Moderate P1272 Nissan · Powertrain The front air/fuel ratio sensor on bank 1 isn't sending a usable, moving signal to the Nissan… Moderate P1273 Nissan · Powertrain Nissan's ECM sees the front air/fuel ratio sensor on bank 1 reading lean for too long and flags… Low