Hello all, before I start ranting on, please do not send me a list of the engine light codes, I have these and im still none the wiser as its not what it looks like on the surface.

After a long time of buying parts for my car i eventually got them fitted all at once (2 days work) and got the car mapped the following day. All seems good on the mapping day bar a misfire engine light which my mapper informs me is the NPS (neutral position switch) due to the newly added power gains. So the mapping continued and eveything seemed to be fine bar this light which keeps coming up

Varies between the below, sometime one, two, three or all four come on at once!! (irregual pattern)

P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected

P0304 Cylinder 4 Misfire Detected

Weeks later i got the NPS replaced and a Lambda sensor which was also flashing up a 'P' code (can not recall which). Anyway the car still pulls and drives fine although I got the garage to also fit a STI TMIC on (not yet re-mapped). All seemed good for 3 days, then I took the car to the Rolling Road (RS Tuining group buy on here) where engine check light retured and also put the car into limp mode.

I can only recall one time when it felt as though it was sluggish and lacking power, however I would not say it was missing at all. I have spoke to the garage that have done almost all my work on the engine and they said for me to take it back on again, but as it is a 130mile round trip I can not be bothered, but then i have paid for a new NPS that hasnt worked, or has it?? mqaybe its something else

Basically can anyone else help me here with an suggestions as im completly lost what to do.

I think it is also worth noting that the other day the engine check light came on for 2 of the 4 misfire codes when i was hardly powering down (little torque in my opinion)

Rob

 

sounds like a spark plug issue,have you checked them they may need replacing

 

Hiya thanks for the info .

The engine was rebuilt in July last year and has only covered 4500miles ish. So I hope its not the plugs.

I though maybe coil packs and plugs myself, I'll await further feedback from other members before jumping to replacing these.

Rob

 

help please

 

up

 

swop your plugs about see if it changes the p codes

 

plug gaps probably or wrong type of plug fitted on rebuild, the chances of all four coil packs being faulty????

change the plugs only an hour knuckle skinning job

 

You could ask JGM or AN other ?

Don't faulty NPS's throw misfire codes up ?

Sorry no real help.

dunx

 

Hiya guys, I appreciate all your advise ^^ Might just try the plugs anyway.

Dunx i believe that you are correct and thats why I have had this replaced, but its still flashing up with the misfire codes.

The garage that carried out the work only specialise in Subarus.... Ive recently had STI Pinks fitted (supplied by Harvey), do you think this could be it?

Had quite alot of work done in the last couple of months so it could be related any of these....STI Pinks, 3" decat full system, STI decat Up pipe, VF30, Walbro, Mapped.

Engine built and fitted in July last year inc new obvious parts such as plugs, belts, pumps etc.

Help required please

Rob

 

You could buy one new/good coilpack and "move it around" to see if a pattern emerges, i.e. all four are goosed ?

dunx

P.S. check they are fastened on properly to !

 

Right decision made, Onto Scoobyteknix next week for another new NPS to ensure that its defiantly not this at fault, turn off the engine check light, and give it a good few runs local to the garage to see if the light returns. If it does I may replace all the coil packs there and then....

This is really starting to p_ss me off. I know having a scoob (~Owned three) when modding is a bit of a roller coaster, but these issues are normally straight forward - engine checks says blah blah, you fix or replace blah blah simples

Thanks for the input guys, unless anymore suggestions are put forward before mid next week im off to Fleetwood

Rob

 

Hey! i know what you mean about engine check light! mine puts up p0546 every so many thousand miles, as i removed the EGT sensor when putting a decat up pipe in so have to turn the check light off each time lol

 

I could live with that^^. The code is random between all four cylinders which i find frustrating. Maybe its just a fauty replacement NPS.

If it was a case of tuning the light off every some many thousand miles id be a happy bunny . But the car goes into limp mode with my issues .

Some good feedback so far though:
Spark Plugs
Coil Packs

I was just hoping someone may have experienced the same and managed to find the remedy.

 

Ask Andrew Carr if it's possible to "delete" the fault code from being "active" in the ecu....

I read on here that Bob Rawle, had/could/tried to "delete" a lambda (removed) fault as stated.

HTH

dunx

 

hi mate i have an 02 sti and was totally standard in every way,bought it september 08.anyhow after a month or so 0304 missfire on 4 comes up and i thought **** here we go,i must of had it turned off/reset about 10 times but kept coming back,then started to tune the car and got exhaust,pump,plugs,filter fitted and remap by simon (JGM) when mapped the light come on and simon nocked it off,he said that he could not see a missfire and fuelling was spot on so werent bothered,anyhow after a few months it started to come on again so was fed up with it so wanted to sort.spoke to jgm and he informed me it woulds be the nps switch so had that done and guess what ? it come bak next day,well spoke to a few well known mappers and was told that it may suffer from the cel light coming on for no reason and to have it turned off in the map for good ! i got simon to do this about 9 months ago and car is cel free and pulls and drives fantastic to this day.i know what its like as you dont want to drive car hard with cel on if at all.i tried all the swapping over of coils and checking plugs and it p1ssed me off for months.not sure if its same situation as yours as you have gone into limp mode but wanted to tell you my story if it helps at all.good luck mate with it.carl.

 

Thanks Dunx, This flashed up during mapping and he didnt say this was possible to delete. I would sooner try and solve the problem at source for the piece of mind, especially as I plan on throwing more power out soon.

I've even started to make moves to sell my new wheels, racing slicks and brembos that havent been fitted to a car as im getting pissed with it lol.... Im just frustrated. maybe is becuase im working a ten hour shift until midnight on birthday !

 

I have seen those codes come up before with rich misfire conditions and faulty plugs (gaps wrong) but if it is driving well it is easy to switch the CEL's off for those along with lambda, EGT, TGV and any other CEL code that is giving spurious warnings.

 

Thanks Carl for the above, much appreciated for taking the time to type it all out. Sounds very simular, the Limp mode has only happned a handful of times. First time was at RS tuning on the Rolling Road. The car pulled to around 292.9bhp on the first run. The 2nd and 3rd run hit limp mode no more than 200bhp. which offered the cells flashing. Then the only time it felt as though the car was lacking power was once on the road. So all in all its only gone into limp a few times. But the cells flash alomst everyday, albeit the light is permanently on.

*ive just missed a call from Andy Carr... will ring him now

Cheers
Rob


No misfire detected on the mapping day, Scoobyteknix built my engine and fitted it. This is all the do all day long, so I can not imagine ive got the wrong plugs. I could imagine that the newly fitted NPS switch being faulty though... Thanks again

going to speak to Andy C now.

Rob

 

Problem resolved, Neutral Position switch was faulty including the one a reputable garage actualy fitted too!!!!