Check engine?

[toast boy]

I've got a 1999 9-3 and intermittently get the check engine light appearing while driving. There's no discernible impact in performance and the light often comes and goes multiple times in a single journey. It doesn't seem to have any correlation to engine temperature or driving style and it never stays on for the duration of a journey, only for a few minutes at a time at random intervals. Does anyone have any ideas of things I could check/replace to remedy this without a diagnostic tool?

Thanks

[DavidY]

I'd suspect DI cassette, the engine keeps a check on misfires and when this counter reaches x in however many if will put on the check engine light, if you continue driving and it drops below the x threshold it will clear the light

[aeropilot]

Yup....DI cassette would be most likely. Same symptoms I had with mine, and it gradually became more often and regular, so I replaced the DI cassette.

[toast boy]

Thanks for the replies. Mine doesn't have a DI cassette, so I'll change plugs and check dizzy/leads and see if there's anything obvious there. Might there be anything else I should be looking at?

[fastcars_hardy]

what engine have u got then

[aeropilot]

toast boy said:

Thanks for the replies. Mine doesn't have a DI cassette, so I'll change plugs and check dizzy/leads and see if there's anything obvious there. Might there be anything else I should be looking at?

I'm guessing then you've got either the B204I or B234I non-turbo engine then....?

I must admit I thought they still used a DI cassette...?

[JensenA]

A bad earth on the ECU can cause a 'Check Engine' message. Check the earth lead, it cured the fault on mine.