The owner of this 2007 Renault Modus 1.6 was not budgeting for any problems, and so was pretty upset when she came to see me. The engine management light had flicker on and did not go out again. 

The fault code stored, P0303, indicated that the problem was with cylinder 3. As the owners finances were tight, I decided the first move would be to swap the coil packs and spark plugs around between cylinders 2 and 3. This saves replacing parts unnecessarily and will give a good indication of what maybe at the source of the problem.

With the coil pack and plugs swapped round and the codes cleared, the engine was fired up again. The same P0303 code was flagged up. This narrowed the problem down, leaving the most probable reason to be an injector or a wiring fault.

The job to remove the injectors on this engine is just under an hour and a half, but it was worth the trouble. When the injectors were swapped around, a new code of P0302. Once the injector that had originally been in cylinder 3 had been replaced, all was well again.

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