Loss of power under acceleration
Car feels sluggish, throttle response is weak, passing feels impossible — possible causes and OBD codes.
Sudden or gradual power loss is a wide symptom. It can originate from the engine, turbo, fuel system, or even the automatic gearbox. OBD-II helps narrow it down.
Top causes: (1) clogged air filter or dirty MAF sensor; (2) slipping automatic transmission (RPMs climb but car doesn't accelerate); (3) turbo underboost (P0299) — worn boost control solenoid or intercooler leak; (4) partially clogged injectors; (5) restricted DPF or catalyst.
Live data: TPS (throttle response), MAP/MAF at WOT, boost pressure if turbo, STFT/LTFT. With P0299 check Live Boost via Mode 01 or enhanced PID.
First diagnostic steps
- Read all stored and pending codes
- Check MAF g/s at wide-open throttle (spec depends on displacement)
- Inspect air filter and intercooler hoses for leaks
- Check Live Boost PID (turbo) or MAP pressure (N/A)
- Read LTFT at multiple loads (idle / 2500 RPM / WOT)
Likely fault codes
Click a code for detailed description, causes, and diagnostic plan.