OBD-II code · Powertrain (generic, extended)
P26FB EGR Cooler Bypass Control Stuck Closed Bank 1
The EGR cooler bypass valve on bank 1 is stuck in the closed position. EGR gas always passes through the cooler, which slows engine warm-up and can degrade cold-start emissions.
Is it safe to drive with P26FB?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyValve flap seized closed by soot
- PossibleActuator linkage jammed in closed position
- Less likelyCarbon or debris buildup preventing free movement
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1.5–5.5 h
- Emissions test
- Likely to fail
- Parts involved
- Egr Cooler Bypass Valve B1, Bypass Actuator
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.