I have a 94 WRX which I have had for a couple of months. Initially the check light came on infrequently and after about 150 miles it came on less frequently to virtually not at all. It came on for a few seconds and then went off almost as quickly indicating an intermittent problem. The local Subaru garage did a check on their ECU system and everything was okay.

I suspect that it was because it was running on 97 octane rather than 100 octane and the ECU was getting used to it.

I have just changed the cambelt and plugs and have had a misfire for the first ten miles or so which seems to have gone but the check light has been coming on more frequently. Although the more miles driven the less frequently it comes on.

It tends to happen on a trailing throttle but not always. Obviously I am concerned as you shouldn't drive with the checklight on - if you stop and turn the engine off the check light stays off, so there is no regular pattern.

Any ideas?.

 

See what fault codes the car has?

http://www.saxonfields.freeserve.co....iag%20Page.htm tells you how to do this.

 

No codes appear just the engine checklight coming on.

 

Looked at the website but confused - not difficult for a newcomer to Scooby's!.

Under ECU Diagnostics and ECU Reset where are the "connect read memory connectors" and "connect read memory connectors & test mode connectors" and once I find these will it all make sense - as it doesn't at the moment.

Presume the story about disconnecting the battery for an hour or more will reset the ECU is a load of bull!.

 

YHM. With a bit of luck, it explains the missing bits from Chris' web page...

Disconnecting the battery does reset the ECU, but if there are stil problems with the sensors you'll be no better off.