P0299
Turbocharger/Supercharger A Underboost Condition
Turbo / boost control
Generic OBD-II
High
What it means
P0299 means the engine isn't producing the boost pressure the ECM expected from the turbocharger or supercharger. The most common cause is a leak in the charge-air plumbing, but a stuck wastegate, faulty boost-control solenoid, or a restricted intake can also be to blame. Expect reduced power until it's fixed.
High
Can I keep driving? The car will run but feels sluggish and may drop into reduced-power limp mode; you can drive gently to a shop, but avoid hard acceleration until it's fixed.
Common symptoms
What you'll notice
- Check-engine light on
- Noticeable loss of power and slow acceleration
- Hesitation or lag under load
- Reduced-power limp mode on hard throttle
Common causes
Most likely first
- Boost leak — split or loose charge-pipe, intercooler hose, or clamp (most common)Likely
- Sticking or worn wastegate or boost-control actuatorCommon
- Faulty boost-control solenoid or vacuum linesCommon
- Restricted intake or exhaust, or a clogged air filterLess often
- Dirty or failing MAF sensor misreporting airflowLess often
- Worn turbocharger or supercharger (bearing, vanes)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame and compare commanded vs actual boost to confirm the underboost.
- Pressure- or smoke-test the charge-air system for split hoses and loose clamps between the turbo and intake.
- Check the wastegate/boost-control actuator and solenoid for free movement and proper vacuum, and inspect the control lines.
- Inspect the air filter and intake/exhaust for restrictions; clean or test the MAF sensor.
- Only condemn the turbo itself after leaks and controls are ruled out; clear and road-test.
FAQ
Quick answers
Is it safe to drive with P0299?+
Short, gentle driving is usually okay, but a stuck-open wastegate or leak means poor power and possible limp mode, so get it diagnosed soon.
Can I just clear P0299?+
It returns the next time the engine can't make its target boost. Find the leak or control fault first, then clear it.
Related codes
Often seen with P0299
Read & clear P0299 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX