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)
P1E00
Chevrolet · Powertrain
Volt/Bolt pointer code: the hybrid/EV controller found a fault and asked for the check engine…
Moderate
P2002
Powertrain
The ECU thinks the diesel particulate filter isn't trapping soot properly — or it can't measure…
Moderate
P2004
Powertrain
The intake runner or tumble flaps stay open when told to close, usually a vacuum or linkage…
Low
P2006
Powertrain
The intake swirl or runner flaps stay shut when the ECU wants them open, choking airflow…
Moderate
P200A
Powertrain
The ECU switched the intake runner flaps but the system didn't respond the way it should.
Low
P2015
Powertrain
The sensor on the intake manifold flaps reports a position that doesn't match what the ECU…
Low
P204F
Powertrain
The DEF/SCR system isn't cutting NOx the way it should; ignored, it leads to a severe speed…
Moderate
P20EE
Powertrain
The SCR catalyst isn't removing enough NOx; DEF quality, dosing, a NOx sensor or the catalyst…
Moderate
P2100
Powertrain
The computer can't push current through the throttle motor – the circuit to the throttle body…
High
P2101
Powertrain
The throttle plate isn't reaching the position the computer asks for, fast enough or accurately…
Moderate
P2102
Powertrain
Too little current or voltage reaches the throttle motor – usually resistance in the feed, not…
Moderate
P2103
Powertrain
The throttle motor circuit draws too much current – a short, a shorted motor or a plate that…
Moderate
P2104
Powertrain
A fail-safe has locked the engine at idle and the gas pedal no longer works – another code…
High
P2106
Powertrain
Reduced-power limp mode: the PCM caught a throttle or pedal fault – look for the companion code.
Moderate
P2107
Powertrain
The processor supervising the electronic throttle failed its self-check – a computer fault, not…
High
P2108
Powertrain
The throttle control module isn't performing as expected – check its power, data link…
Moderate
P2110
Powertrain
The PCM is capping engine speed with fuel cut-off because it can't fully trust or close…
Moderate
P2112
Powertrain
The PCM asked the throttle to open, but it stayed shut – the engine can't get air, so it bogs…
High
P2118
Powertrain
The throttle motor is drawing more or less current than the PCM expects to hold the plate where…
Moderate
P2119
Powertrain
The throttle plate isn't reaching the position the PCM commands, or won't spring back to its…
Moderate
P2120
Powertrain
The PCM lost a usable signal from the main gas pedal sensor, often only for a moment.
Moderate
P2121
Powertrain
The main gas pedal signal stays within normal voltage but moves in a way a real pedal can't.
Moderate
P2122
Powertrain
The main gas pedal sensor reads close to 0 volts, below anything a working pedal produces…
Moderate
P2123
Powertrain
The main gas pedal sensor reads near its full 5-volt supply or higher, even with your foot off…
Moderate
P2125
Powertrain
The PCM lost a valid signal from the second, cross-check sensor in the gas pedal.
Moderate
P2127
Powertrain
The second gas pedal sensor dropped below its minimum voltage, so the PCM can't verify pedal…
Moderate
P2128
Powertrain
The second gas pedal sensor reads above its allowed maximum, so the pedal position can't be…
Moderate
P2135
Powertrain
The two position signals inside the throttle body disagree, so the PCM can no longer trust…
Moderate
P2138
Powertrain
The two sensors in the gas pedal report different pedal positions, so the PCM limits throttle…
Moderate
P2146
Powertrain
The shared power feed for one group of injectors is open, so every injector in that group has…
High