OBD-II code · Powertrain (generic)
P04A3 Exhaust Pressure Control Valve B Intermittent
Same as P049F with intermittent or erratic feedback - typically a connector or harness fault.
Is it safe to drive with P04A3?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyIntermittent contact at connector or terminal
- Less likelyConnector with intermittent contact under vibration
- Less likelyHarness routed against vibrating component
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.8–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Exhaust Pressure Valve B, Exhaust Pressure Wiring B
Related codes
- P0479Exhaust Pressure Control Valve A Intermittent
- P04A0Exhaust Pressure Control Valve B Range or Performance
- P04A1Exhaust Pressure Control Valve B Low
- P04A2Exhaust Pressure Control Valve B High
- P04A4Exhaust Pressure Control Valve B Stuck Open
- P04A5Exhaust Pressure Control Valve B Stuck Closed
- P04A6Exhaust Pressure Control Valve B Position Sensor Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.