Had to get towed home last night My MY93 WRX is only running on 3 cylinders. I was giving it a bit of stick at the time, then lost power and coasted to a halt. The engine will still start and run its not making any nasty noises and theres no smoke coming out the back. My thoughts are electrical, maybe coil pack? (hopefully!) Does anyone have any suggestions? I'm a bit worried because I knew I had slightly to much oil in the engine maybe just under 1/2 a litre to much, was going to drain it out today but now this has happened. Could this play a part at all?

 

check a lead hasn't come loose
could be plug or coil pack

take a plug lead off one at a time and start car untill you find out which cylinder is failing.

 

my 03 sti did this and a plug had worked its way loose.