Check Engine Light

[Buck R]

Hi all !

This is my first Topic so here goes.

I have a 1999 series 2 Stagea rs four s manual and the " check engine light " has been coming on lately. I have had one mechanic say it was the O2 sensor - so I have replaced it. The problem has not been fixed.

The computer test equipment results show no faults. Has anyone had any similar problems with their cars ?. It has also been suggested that there could be a bad earth somewhere in the coil plug packs or their wiring loom.

Any help would be greatfully excepted.

BuckR

[wolverine]

It is probably a coil pack issue.

What test equipment was used? Was it data scan through the consult port?

[Buck R]

Thanks for the ideas.

Yes it was done via the consult port ( the one near the fuse panel behind the coin tray ). If it was a coil pack wouldn't i have a miss or hunting at idle or break down at high rpm ? What about exhaust pops on back off when the engine is cold ?

[wolverine]

Usually it will be an issue under load when it comes to coils.

However I had the same issue when the RS4S arrived from Japan. There was an intermittent check light.

Consult was indicating a CAS issue but it was checked and was fine. At some point when the coils were replaced the issue resolved.

There are some cheap fixes for coils such as spraying them with urethane seal coat (CRC product) and checking the plugs/wiring to the coils. It might not be the issue but it is worth trying the cheap options like this as a starting point.