P2E59: Cylinder 1 Alternative Fuel Misfire Detected

What it means

Misfire detected on cylinder 1 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 detects combustion by monitoring crankshaft speed while the engine runs on alternative fuel. P2E59 identifies a misfire assigned specifically to cylinder 1, so its alternative-fuel injector and supply to that cylinder deserve particular attention.

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 1 misfire counts and review freeze-frame data, including fuel mode and engine load.
2. Compare operation on alternative fuel with operation on petrol; a cylinder 1 misfire only on alternative fuel narrows the search to its alternative-fuel delivery.
3. Inspect cylinder 1's alternative-fuel injector connector and wiring for looseness, corrosion, damage, or signs of leakage.
4. Check alternative-fuel quality and supply pressure, particularly if the fault followed refuelling or appears under load.
5. Test cylinder 1's alternative-fuel injector operation and compare its delivery with other cylinders and the manufacturer's specification.
6. If cylinder 1 also misfires on petrol, check its ignition components and compression before concluding the alternative-fuel system is at fault.

Common fixes

• Repair a loose or damaged connector or wiring at cylinder 1's alternative-fuel injector.
• Refill with known-good alternative fuel if contamination or poor fuel quality is suspected.
• Clean or replace cylinder 1's restricted or weak alternative-fuel injector after confirming the fault.
• Repair a pressure or regulation problem affecting alternative-fuel delivery if testing identifies one.

Can I keep driving?

Avoid heavy acceleration, and stop driving if the check-engine light flashes or the engine shakes severely because continued misfiring can damage the catalytic converter. If the vehicle runs smoothly on petrol, use that mode if available and have the cylinder 1 fault checked soon.