Loss of power: Codes, Causes & Fixes
Noticeable loss of power usually has one of a few causes: the engine computer has entered limp mode, a turbocharged engine is underboosting (P0299), airflow is restricted by a dirty MAF sensor or clogged air filter, fuel pressure is low, or the exhaust is blocked by a failing catalytic converter or full diesel particulate filter. Read all stored codes and freeze-frame data first – they usually show which of these paths to follow.
214Codes
3.1Average severity
22%High or critical
9%DIY-friendly
Severity distribution
Most viewed
P0174
Powertrain
The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction…
Moderate
P0420
Powertrain
The bank 1 catalytic converter no longer stores enough oxygen to clean the exhaust properly.
Low
P0101
Powertrain
The MAF sensor's airflow reading doesn't match what the engine computer expects…
Low
P0171
Powertrain
The engine computer is adding the maximum extra fuel it's allowed on bank 1 and still sees…
Moderate
P0299
Powertrain
The turbo or supercharger isn't building the boost pressure the engine computer is asking for.
Moderate
P0300
Powertrain
The engine computer sees misfires that jump between cylinders or hit several cylinders at once.
High
All codes (214)
P0174
Powertrain
The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction…
Moderate
P0182
Powertrain
The fuel temperature signal is pulled close to 0 V, so the engine computer thinks the fuel…
Low
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
P0193
Powertrain
The rail pressure sensor signal is stuck near the 5-volt limit, above anything a working sensor…
Moderate
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
P0217
Powertrain
The engine overheated. Stop driving: continuing can warp the head, blow the head gasket…
Critical
P0221
Powertrain
The second throttle angle signal leaves its window or stops following the plate, so power…
Moderate
P0231
Powertrain
Voltage on the wire feeding the fuel pump is too low while the pump is supposed to be running.
High
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
P0243
Powertrain
The engine computer found a fault in the electrical circuit of the solenoid that controls…
Moderate
P0246
Powertrain
The wastegate solenoid control circuit reads too high, usually a short to power or a shorted…
Low
P0263
Powertrain
Cylinder 1 is producing noticeably more or less power than the others, beyond what fuel trim…
Moderate
P0269
Powertrain
Cylinder 3 isn't pulling its weight, or is pulling too hard, and the fuel correction for it…
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
P0300
Powertrain
The engine computer sees misfires that jump between cylinders or hit several cylinders at once.
High
P0301
Powertrain
Cylinder 1 is repeatedly failing to fire. The cause is almost always its coil, plug, injector…
Moderate