P3422Cylinder 3 Exhaust Valve Control Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P3422 would apply if cylinder 3's exhaust valves disregard an order to stop or restart even though the wiring checks out. No manufacturer documents this code publicly. How such a fault can be spotted is shown in patents: Ford patented a way to catch an exhaust valve still lifting after shutdown by its mark in the exhaust pressure trace; the engine then brings the cylinder back, blocks further deactivation and may store a code. A Delphi patent does the same for the intake side by timing pressure pulses against crank angle. GM folds both valves of cylinder 3 into one mechanical check, P349A. A leaking exhaust valve pumps air through the cold cylinder, which upsets fuel trim and can cause a misfire count on cylinder 3.
- What you may notice
- Uneven running in reduced-cylinder mode
- Fuel trim or misfire codes alongside
- Check engine lamp on
- Likely causes
- PossibleExhaust-side switching lifter or rocker of cylinder 3 stuck
- PossibleOil level or quality outside specification
- RareRestricted oil passage to the exhaust switching element
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.