Subaru has dumbfounded me.

[2themoon]

Ok so I got a few problems with my 1998 Wrx STI, I know a little but not alot.

Here goes, Morning start up is fine, then I drive for 5 minutes and it brings up a cel. I park up at work for 8 hours, come back to car and when I start it its like it idles very very low and cuts out sometimes until its warm, it produces this same symptom everyday.

I connect the 2 black diagnostic plugs to see what code it throws, it throws code 24 Idle air control valve ( I have tried multiple IACV\'s )

I clear the code, drive again and it comes back, I notice it is more likely to come back when I am changing down through the gears 3rd to 2nd.

I disconnect the black connectors and connect the green ones and drive the car for a couple of minutes, it throws another cel code 51 Neutral Position Swiitch.

I turn the car off, with ignition on I depress the acceleration pedal then bring it back up half way for 2 seconds, then I start the car and hold the revs at 2000rpm for 1-2 minutes then it throws another cel code 33 Vehicle Speed Sensor, The speedo still works fine.

I was wondering if anyone can shed some light on this situation, as I have already changed the neutral position sensor and I still get the same code reoccurring ?

Could any of the above sensors be causing the others to bring up a cel ?

Would love some input

Cheers ;D

[kamineko]

sounds like an earth wiring fault. you\'ll probably find all those sensors are fine

[2themoon]

I have checked the earths from the chassis to the bellhousing and cleaned them also I have run a earth from the alternator to the chassis, is there any other place were I could ground it ?

[kamineko]

yeah, never easy to find..

as a matter of course, also check/clean the negative battery terminal to chassis

has the engine been out lately? behind the battery are a bunch of plugs that join the chassis loom to the engine loom. cycle those.

also your ecu plugs, in the passenger footwell. check for moisture down there incase the A/C drain is dislodged

this is just common advice. sorry i don\'t have the actual cure

[Stoffa]

Maybe engine coolant temp sensor. cheap to replace

[2themoon]

Cleaned the earth points no problems with earth. Tested ecu for ground on all terminals, and at plug connections all earths fine they all are very earthy, re wired extra earths to engine and rear of trans, still getting cels.

I think its time to burn it.

I realize now why the previous owner got rid of it.

It had a bag of sensors in the glove box, I guess he tried changing them all as well and got pissed off.

Can anyone please recommend a Subaru dealer or Mechanic that actually knows there stuff and has awesome diagnostic skills meaning they do not swap out parts guessing its this or that ?

[dean.ryan]

Tried resetting the ecu / trying a different one?

[2themoon]

Today I followed the loom from the NPS, turns out the loom to the sensor was broken, found both wires broken up under the dash, god knows how that happened. So all sorted now, check light blinks rapidly no fault codes, so glad I found that ;D that one sensor can cause so many other faults.

Thanks everyone for their input much appreciated ;D