Poor fuel economy: Codes, Causes & Fixes
When mpg drops without a change in driving habits, typical culprits are a thermostat stuck open (P0128), a slow oxygen sensor, a coolant temperature sensor reading too cold, dragging brakes or simply low tire pressure. Several of these set no code at first, so compare your recent fill-ups and check tire pressure against the placard on the driver's door jamb. A stored code, if present, narrows the search considerably.
146Codes
2.4Average severity
2%High or critical
17%DIY-friendly
Severity distribution
Most viewed
P0011
Powertrain
The bank 1 intake cam sits further advanced than the PCM asked for, usually an oil or control…
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
P0172
Powertrain
The engine computer is pulling as much fuel as it's allowed on bank 1 and the mixture is still…
Moderate
P0113
Powertrain
The intake air temperature signal is stuck at maximum voltage, which usually means an open…
Low
P2002
Powertrain
The ECU thinks the diesel particulate filter isn't trapping soot properly — or it can't measure…
Moderate
All codes (3)
P0300
Powertrain
The engine computer sees misfires that jump between cylinders or hit several cylinders at once.
High
P2463
Powertrain
The DPF is loaded with more soot than the ECU allows; it needs a regen or cleaning before it…
High
P3000
Toyota · Powertrain
Toyota's hybrid computer flags a fault in the high-voltage battery system and limits hybrid…
High