my bugeye 2002 sti type uk has developed a misfire on cylinder 1 fault code p0103 on idle ive tried neutral position sensor, coolant temp sensor, new plugs (grade 7), cleaned idle control and MAF and light is back on same code p0103, out of ideas can anyone help

 

coil pack failed?

 

My mate had this and it turned out to be a cracked piston If all else fails try doing a compression test.

 

hi mate think that code is MAF sensor fault, although it may not be the sensor its self something else maybe effecting the way it works, have you checked for air leaks etc and good connections to the MAF and no broken wires etc, does it clear when the revs are increased??

 

light is on all the time, but will check all pipes and wires, cheers

 

no i meant does the misfire clear once the revs are increased!

 

also going to swap cylinder 1 coil pack with cylinder 2 and see if fault reads different

 

sorry yes no missfire on acceleration

 

Hate to say it, but do try a compression test. I had similar symptoms on my P1 which turned out to be a bent valve

 

I did think about yours too but on Cliff's you couldn't feel or hear the misfire and his was throwing up the same fault code. Cliff ran his up the quarter mile with that cracked piston thinking it was the neutral position switch because it felt like nothing was wrong.