Fuel & Air Metering Trouble Codes: List & Fixes
These codes (mostly P00xx–P02xx) cover how the engine computer measures incoming air and meters fuel: the mass airflow and manifold pressure sensors, oxygen sensors, fuel trim, fuel pressure and injectors. Lean codes such as P0171 and P0174 are very often caused by an unmetered air leak – a cracked intake hose or vacuum line – rather than a failed sensor. Check hoses and the air filter housing before buying parts.
193Codes
2.5Average severity
7%High or critical
26%DIY-friendly
Severity distribution
Most viewed
P0174
Powertrain
The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction…
Moderate
P0011
Powertrain
The bank 1 intake cam sits further advanced than the PCM asked for, usually an oil or control…
Moderate
P0021
Powertrain
The bank 2 intake cam is more advanced than commanded or slow to respond; compare it with bank…
Moderate
P0014
Powertrain
The bank 1 exhaust cam won't follow its target and stays too far advanced; think oil, valve…
Moderate
P0101
Powertrain
The MAF sensor's airflow reading doesn't match what the engine computer expects…
Low
P0093
Powertrain
Rail pressure is dropping faster than injection explains: fuel may be escaping. Stop and check…
Critical
All codes (193)
P2227
Powertrain
The baro sensor's reading doesn't agree with the other pressure sensors or with what the engine…
Low
P2228
Powertrain
The baro sensor signal is below its valid range, as if the car were far higher than any road…
Moderate
P2237
Powertrain
The wire that carries the pump current of the upstream wideband (air-fuel) sensor is open.
Low
P2238
Powertrain
The pump-current wire of the upstream air-fuel sensor is being pulled low, usually by a short…
Low
P2243
Powertrain
The ECM lost the reference-cell signal of the upstream wideband sensor, as if the wire were…
Low
P2262
Powertrain
The engine computer commanded boost but saw almost none, pointing to a mechanical turbo…
Moderate
P2263
Powertrain
Boost isn't tracking its target closely enough: too low, too high or too slow to respond.
Moderate
P2270
Powertrain
The oxygen sensor after the catalytic converter won't show rich, even when the PCM deliberately…
Low
P2271
Powertrain
The sensor after the converter stays rich even while coasting with the fuel cut off, when it…
Low
P2279
Powertrain
Air is getting into the engine after the mass airflow sensor, so the computer isn't measuring…
Low
P2293
Powertrain
The second fuel pressure control stage can't hold its target; on VW/Audi 2.0T often…
Moderate
P2646
Powertrain
The engine asked VTEC to switch to the high-lift cam, but the oil pressure switch never saw…
Low
P2647
Powertrain
The VTEC oil pressure switch reports the high-lift rockers engaged while the engine computer…
Moderate