Fuel & Air Metering Trouble Codes: List & Fixes

P0135 Powertrain The heater inside the upstream oxygen sensor on bank 1 isn't working or its circuit is faulty. Low P0174 Powertrain The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction… Moderate P0113 Powertrain The intake air temperature signal is stuck at maximum voltage, which usually means an open… 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 P0299 Powertrain The turbo or supercharger isn't building the boost pressure the engine computer is asking for. Moderate

P0152 Powertrain Bank 2's front O2 sensor is pinned high – usually voltage leaking in from its heater wire… Moderate P0170 Powertrain Bank 1 fuel correction is far outside its normal window, lean or rich, and the ECU won't say… Moderate 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 P0173 Powertrain Fuel correction on bank 2, the side without cylinder 1, is out of range or unstable, lean… Moderate P0174 Powertrain The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction… Moderate P0175 Powertrain Bank 2 is still running rich even though the PCM is already cutting fuel on that side as far as… Moderate P0190 Powertrain The signal from the fuel rail pressure sensor has dropped out or become unusable to the engine… Moderate P0191 Powertrain The rail pressure reading is electrically valid but doesn't make sense for how the engine… Moderate P0192 Powertrain The rail pressure sensor signal voltage has fallen below the lowest value a working sensor can… Moderate P0193 Powertrain The rail pressure sensor signal is stuck near the 5-volt limit, above anything a working sensor… Moderate P0200 Powertrain The ECU found a fault in the injector control circuits that it can't pin on one cylinder, often… High P0201 Powertrain The ECU sees an open or faulty electrical circuit to injector 1, so cylinder 1 is probably… Moderate P0202 Powertrain Injector 2's circuit is open or out of range; on an inline-four it's a middle cylinder under… Moderate P0203 Powertrain The ECU sees no normal electrical response from injector 3: its coil, its wiring or its driver… Moderate P0204 Powertrain The circuit to injector 4 is open or out of range; on most transverse engines that's… Moderate P0205 Powertrain The ECU sees a broken or faulty electrical circuit to the cylinder 5 injector, so that cylinder… Moderate P0206 Powertrain Injector 6's circuit is open or faulty. On an inline-six that's the rear cylinder, tucked under… Moderate P0207 Powertrain The ECU lost normal control of injector 7, which only exists on V8 and larger engines. Moderate P0208 Powertrain The circuit to injector 8, the rear cylinder on bank 2 of a V8, is open or doesn't respond… Moderate P0216 Powertrain The ECU can't control or confirm injection timing, usually on a diesel with an electronic… High P0221 Powertrain The second throttle angle signal leaves its window or stops following the plate, so power… Moderate P0230 Powertrain The engine computer found a fault in the circuit it uses to switch the fuel pump relay or pump… Moderate P0231 Powertrain Voltage on the wire feeding the fuel pump is too low while the pump is supposed to be running. High P0232 Powertrain The fuel pump feed wire has voltage on it when the engine computer has switched the pump off. Moderate P0234 Powertrain Boost rose above the safe limit the engine computer allows, so it may cut power to protect… High P0235 Powertrain The engine computer found an electrical fault in the boost pressure sensor's wiring… Moderate P0236 Powertrain The boost sensor's signal is electrically OK, but its readings don't make sense compared… Moderate P0237 Powertrain The boost sensor signal has dropped near zero volts, reading less pressure than the atmosphere… Moderate P0238 Powertrain The boost sensor signal is stuck near 5 volts, so the computer sees impossibly high boost… Moderate