P0299 Code: Turbocharger Underboost — Causes & Fix
P0299 means the turbocharger or supercharger is producing less boost than the ECM commands (underboost).
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $60 – $1,200
- Time to fix
- 30 minutes – 2 hours
What it means
Causes include a boost (intercooler) leak, a stuck-open wastegate, a failed turbo, a clogged air filter, or a boost control fault. P0299 is a generic OBD-II powertrain code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer petrol car or light truck regardless of make. Fix the underlying fault, then clear the code with an OBD-II scan tool — it will return if the problem isn't resolved.
Symptoms
- Check engine light on
- Noticeable lack of power / sluggishness
- Limp mode on hard acceleration
How to fix it
- 1
Check for boost leaks
1. Inspect the intercooler pipes, clamps, and hoses for leaks. 2. Repair any loose or split couplings.
- 2
Test the wastegate and turbo
1. Check the wastegate actuator and boost control. 2. Inspect the turbo for damage, then clear the code.
Frequently asked questions
Is a boost leak the usual cause?
Very often — a popped intercooler pipe or split hose is the most common P0299 trigger. Check those first.
Last updated July 19, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.