A friend's FD with stock ECU, stock injectors is running extremely rich..... can't figure out the problem. All the plugs are firing, changed the coils but still seems to run stinking rich. The injectors are not leaking.

Any ideas what might be going on?

 

well ... the plugs must be firing if the engine is running. maybe it's an issue with the oxygen sensor???? i don't know ... just throwing out ideas.

how do you know it's rich? what are the symptoms?

 

Did he just recently have the fuel filter, fuel line, or fuel pump replaced?