P029E

What it means

P029E means the engine control unit has found that the fuel correction for cylinder 2 has reached its maximum limit. The control unit adjusts fuelling for each cylinder individually, using exhaust sensor or crankshaft speed data, to keep the mixture correct. It could not bring cylinder 2 back on target even at full correction, so it set the code. The correction can be too rich or too lean, and the way each cylinder is monitored depends on the engine.

Symptoms

• Check engine light on
• Rough idle or a noticeable shake at idle
• Hesitation or poor pulling under load
• Possible misfire on cylinder 2 felt or logged
• Increased fuel consumption or fuel smell
• Hard starting or an occasional stumble after starting

Possible causes

• Faulty, clogged or leaking fuel injector on cylinder 2likely
• Intake air leak at cylinder 2, such as a manifold runner gasket, port seal or cracked vacuum hoselikely
• Damaged wiring, poor connector contact or high resistance in the cylinder 2 injector circuitpossible
• Mechanical fault on cylinder 2, such as low compression, a leaking valve or worn ringspossible
• Exhaust leak or a faulty exhaust sensor upsetting the readings the cylinder trim relies onpossible
• Fuel pressure or fuel quality problem that affects cylinder 2 more than the others, depending on engine layoutrare
• Fault in the engine control unit injector driverrare

How to diagnose

1. Read all stored and pending codes and record the freeze frame data. Look for related codes such as misfire on cylinder 2, other fuel trim codes or injector circuit codes.
2. Check live data for cylinder 2 correction against the other cylinders, and note whether it is strongly positive (lean) or negative (rich) and whether it changes with load and rpm.
3. Inspect the cylinder 2 injector connector, wiring and earth for damage, corrosion, chafing or heat damage, and inspect the intake and vacuum hoses around that cylinder.
4. Carry out a smoke test of the intake system, focusing on the manifold seals and ports at cylinder 2, and check for exhaust leaks ahead of the sensors.
5. Test the injector circuit for correct resistance, supply and control signal, and listen for or compare injector operation with the other cylinders.
6. Where the design allows, swap the cylinder 2 injector with another cylinder and see whether the fault follows it.
7. Check fuel pressure against the manufacturer's specification, and for direct injection engines follow the model-specific procedure for high-pressure checks.
8. If the fuelling checks out, carry out compression and leakdown tests on cylinder 2 to rule out a mechanical fault.

How to fix

• Replace or professionally clean and flow-test the cylinder 2 injector if it is faulty, blocked or leaking, following the model-specific procedure.
• Repair or replace leaking intake manifold gaskets, seals or vacuum hoses.
• Repair damaged wiring or connectors in the injector circuit, and clean or secure poor earths.
• Repair the mechanical fault found on cylinder 2, such as valve or piston ring wear, as indicated by the test results.
• Repair exhaust leaks or replace a faulty exhaust sensor if it is confirmed to be giving incorrect readings.
• Correct any fuel pressure or fuel quality problem, then clear the code and road test to confirm it does not return.

Can I keep driving?

Nearby codes

• P029DGenericCylinder 1 - Injector Leaking
• P029FGenericCylinder 2 - Fuel Trim at Min Limit