OBD-II code · Powertrain (generic)
P04A5 Exhaust Pressure Control Valve B Stuck Closed
Same as P04A4 but the valve B is stuck closed - back-pressure stays high even when the engine should run with low restriction; risk of overheating or excessive fuel consumption.
Is it safe to drive with P04A5?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyValve stuck closed due to soot or broken linkage
- Less likelyCarbon or debris buildup preventing free movement
- Less likelyComponent wear with age - mechanical play
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1.5–4 h
- Emissions test
- Likely to fail
- Parts involved
- Exhaust Pressure Valve B
Related codes
- P048AExhaust Pressure Control Valve A Stuck Closed
- P04A2Exhaust Pressure Control Valve B High
- P04A3Exhaust Pressure Control Valve B Intermittent
- P04A4Exhaust Pressure Control Valve B Stuck Open
- P04A6Exhaust Pressure Control Valve B Position Sensor Circuit
- P04A7Exhaust Pressure Control Valve B Position Sensor Circuit Range or Performance
- P04A8Exhaust Pressure Control Valve B Position Sensor Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.