P2E5E: Cylinder 6 Alternative Fuel Misfire Detected

What it means

Misfire detected on cylinder 6 during alternative fuel operation. Specific to bi-fuel CNG/LPG operation.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

The engine controller watches crankshaft rotation for signs of incomplete combustion when alternative fuel is being used. This code assigns the misfire to cylinder 6, which makes its alternative-fuel injector and wiring a priority if the engine runs properly on petrol.

Common causes

Most likely first.

1. Injector clogged or weak
2. Fuel quality off-spec

Symptoms

• Check engine light on or flashing
• Rough idle and uneven running
• Power loss, hesitation under acceleration
• Increased fuel consumption
• Possible smell of unburned fuel from exhaust

How to diagnose it

1. Use a scan tool to confirm cylinder 6 misfire counts and review the freeze-frame conditions and selected fuel mode.
2. Compare engine operation on petrol and alternative fuel to determine whether the cylinder 6 misfire is mode-specific.
3. Inspect cylinder 6's alternative-fuel injector, connector, and wiring for looseness, corrosion, physical damage, or leakage.
4. Check the alternative fuel and supply conditions, especially if symptoms followed refuelling or occur under acceleration.
5. Test cylinder 6's alternative-fuel injector operation and delivery against the other cylinders and the manufacturer's specification.
6. If cylinder 6 also misfires on petrol, check its ignition system and mechanical condition.

Common fixes

• Repair damaged or poorly connected cylinder 6 injector wiring.
• Refill with known-good alternative fuel if the fuel may be contaminated or off-spec.
• Clean or replace the cylinder 6 alternative-fuel injector if testing finds restricted or weak delivery.
• Repair a confirmed alternative-fuel pressure or supply problem.

Can I keep driving?

Stop driving if the check-engine light flashes or the engine shakes severely; continued misfire can overheat the catalytic converter. If petrol operation is smooth, use petrol if the vehicle allows it and have cylinder 6 checked promptly.