OBD-II code · Powertrain (generic)

P029D Cylinder 1 - Injector Leaking

Cylinder 1 injector leaking fuel between commanded openings. A flow-deviating injector throws off cylinder balance — adjacent cylinders run leaner/richer to compensate, often masking the root cause until the trim limit is hit.

Is it safe to drive with P029D?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyInjector seal or nozzle worn

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
1–5 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Injector Cyl1

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.