4age 16v running roughly - diagnostics shows unknown code

[jondee86]

Almost sounds like it is running on three cylinders. Try pulling the caps off the spark plugs
one at a time while the engine is running. If the cylinder is working the engine speed will drop
and the idle will get rougher. If taking the cap off makes no difference then the cylinder is not
working and you can investigate.

If all cylinders are working, but there is a big difference in the sound of the engine when you
take one of the caps off, there may be a mechanical problem with that cylinder.

Cheers... jondee86