Hi everyone new to this and scooby's, just got a impreza sport standard except exhaust from cat back is straight through stainless steel with a BIG *** can and after market air filter,
the problem is every now and then the check engine light pops on when driving, ometimes it will come on for 2-3 mins then go off and wont come back on at all for rest of my journey, then other times it will come on for 5sec then off then back on mins later for 5 secs again then goes off and stays off, any ideas????

 

It sounds like the lambda sensor problem, initially emissions will be high but when the engine heats up they are reduced.

 

What year car?

 

If its a classic you can read the error messages yourself, instructions are here

http://www.subaru-impreza.org/forum/...hru-years.html

worked for me

 

year 2000 seems to run fine just dont wanna brake down!

 

try cleaning lambda sensor or replacing it then see what happens.or put it in diagnostic mode and see what code comes up.