Kevmondo

I have a 2002 bugeye WRX, and when im cruising along the motorway at 60mph dead on, the check engine light comes onand stays on not flashing. Mods at the moment are Power Engineering decat downpipe and the centre pipe is a decat or sports cat, im not too sure, but its deffo not standard, and a standard back box, it also has a ITG panel filter. Fuel wise its using V-Power. It doesnt come on any other time other than at 60 mph. But!, it goes off after 24hrs or so! Does the ECU store it in its memory even though its gone off.? Any ideas why it could be coming on? Thanks.

....the previous owner of a dark blue bugeye Impreza. Reg no is HT02 BZY, his name is Gary Farrar and was a member on here until 20th April 2006. I think he was around this region as it had a Power Engineering sticker in the rear window. Just want to ask a few questions about the car ive bought, nothing sinister. Please PM me. Hope someone can help