Plug a suitable diagnostic device into the obd port and select the section dealing with fuel trim and read off the results - I can't help more than that because I don't have a complete understanding of how to interpret them. I think the fuel trim is the difference between the expected injection duration and the actual duration. I also think it is of a somewhat general usefulness, providing strong clues of faults elsewhere as well as possibly the injectors themselves.
Answers & Comments
Plug a suitable diagnostic device into the obd port and select the section dealing with fuel trim and read off the results - I can't help more than that because I don't have a complete understanding of how to interpret them.
I think the fuel trim is the difference between the expected injection duration and the actual duration. I also think it is of a somewhat general usefulness, providing strong clues of faults elsewhere as well as possibly the injectors themselves.