maybe some one can help???

i have an my93 wrx, the car is standard, but i have developed an stutter on acelaration around the 3k - 4k rev range? i have had the ecu read for fault codes and o2 censor came up, but my cel light on the dash only comes on now and again??

i have been told so many diferant storys, that the o2 sensor would not cause a stutter and it will be the coil packs as these cause that??
can anyone help, bit reluctant to put it into subaru with a blank cheque, (had too many bad experances but thats another story)

any idea's where to start? what to change first to stop this problem, also will it cause major faults if not fixed asap???

 

If you are on boost when it stutters then unlikely to be the O2 sensor unless it is running very lean on cruise and heating the plug tips for example and the stutter is det.. more likely though is stutter is on full boost that it is spark related.. coilpacks or plugs..

 

i had the same problem recently and it was the plugs.... i feel it becomes a bit more evident with the cold weather.

just replace them with sum NGK pfr6b or pfr7b plugs, i noticed the difference straight away.

 

i changed the plugs last week end and it has improved so its looking more towards to the coil packs???

 

have you got any mods? increased boost or anythin? what plugs did u fit? and what gap ?

 

i have no mods (air filtre and dv) thats all the plugs i put in were NGK cant remerber the numbers but were reconmended from here??

 

what dump valve is it? is it a VTA type?

 

its a bailey dump valve

 

what plug gap did you use?

 

the plugs were pre-set???

 

u will find you car will be more hesitant with the bailey dump valve too cause your car overfuels, i used 2 have 1 but the car ran **** with it on, i think i only had it on for a week before i got annoyed and took it off.

try puttin your original dv on for a week or so and see if the running gets any better, u can always swap back if it doesnt.

 

How are your leads?
Big long leads .... they do fall over too.
Try the cheaper options first mate? Take it to a garage with a testbench and have them and the coils looked at, save your time and money.