What does it mean?
P1159 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Misfire Cylinder 8 With Fuel Cut-Off .
Symptoms
- Malfunction indicator lamp flashing during the misfire, then staying on
- Strong shaking and vibration, most obvious at idle and light load
- Clear loss of power and rough, uneven running
- Popping or spitting sound from the exhaust
- Raw fuel smell and heavy fuel consumption before the cut takes effect
Likely causes
- Failed ignition coil or a cracked, tracking spark plug boot on cylinder 8
- Worn, fouled or incorrectly gapped spark plug in that cylinder
- Faulty or clogged injector so the cylinder receives little or no fuel
- Open, shorted or chafed wiring to that coil or injector
- Low compression from a burnt valve, a broken valve spring or a worn piston ring pack
- Vacuum leak affecting only that cylinder, such as a failed intake manifold gasket section
- Carbon build-up on the intake valve of that cylinder disrupting fuel delivery
How to fix it
- Confirm which cylinder is affected in live misfire counters before removing parts
- Swap the ignition coil with a neighbouring cylinder, clear codes and see whether the misfire follows the coil
- Remove and inspect the spark plug for wear, fouling, oil, coolant traces and correct gap
- Swap or test the injector on that cylinder, and check injector circuit resistance and wiring
- Run a compression test and, if it is low, a cylinder leakage test to find where the pressure escapes
- Check the intake manifold gasket area around cylinder 8 for a localised vacuum leak
- Repair the confirmed fault, then clear codes and verify the misfire counter stays at zero on a road test