Hi all, (tried looking for a solution before posting)

Finally got my first Impreza and its been a bit of a nightmare.

4 times the engine management light has come on and I have returned it to the dealer I bought it from and still it has a problem. Hope someone in the know can help as I dont trust the garage to fix it.

Symptoms.

First time driving in town - Misfire cylinder 2
Second, Third, Forth - Leaving or within first mile of petrol station again misfire but usually 2 and 4.

Car had a cambelt by them before I collected it... tooth out? tensioner?
They have so far fitted 4 spark plugs and coils on 2 and 4.

Any help would be great on getting to the bottom of the issue.

Thanks

 

Does it actually misfire or is it just throwing up the CEL light?

 

Never felt it misfire or heard anything.

Today the cel light came on as I started the car after filling up with the mis fire codes. But any other time I start it after i reset the codes it is fine.

 

If they can't fix it can you return it? These things can go on and on...

 

Nah probably not. Car is great apart from this issue.

Maybe something to do with tank pressure or similar following fill up. Once I reset the ecu it will be fine until the next fuel visit. Luckily theres not much time between trying something and testing with yet another fill up required

 

What fuel you are using? If it's 95 or 97 it can be because of that, these cars are quite freaky. I was racing with a Porsche and an AMG in Germany and was driving on 98 and then the light turned on, so called a friend who is a Subaru rally mechanic and he said to only run it on 100 octane and not anything else. As soon as I put 100 octane, the light came off. It can also be the catalyst converter getting too old and the seals can be worn, that's what another subaru specialist told me when the light turns on.

 

Well been running 97 as near me there is no tesco 99 for 30+ miles. Will try a reset though and make the drive out to try when I refuel.

Or better still stick to V Power.

 

Uff that's bad, I don't know why there isn't 100 octane available everywhere in the UK.. Is yours remapped?

 

No seems to feel standard. Would of thought poor octane fuel would just cause it to run a bit rough but not show misfire codes?

 

Sounds like the Neutral Position Switch, NPS, on the gearbox. When these are playing up it tends to throw misfire codes, even though the engine may not be misfiring. They're about £40 for a new genuine one and easy to change on a 5 speed box.

 

Thinking I may put a few things on and see what happens. Not sure I want to go back to the dealer as they have no real clue unless something is hanging off.

 

Taken a data log from the car and if anyone is able to take a look and spot any problems I would be happy to email it over.

Filled up at Tesco this time and got misfire pending on 2 and 4 but no light this time...

 

Below is a graph of the data run if anyone can see something that looks wrong please let me know. Thanks

https://drive.google.com/file/d/0B4R...ew?usp=sharing

 

I had the same on a 2002 wrx cambelt was a tooth out same side was Misfiring too

 

Oh right. Well I have been thinking it seems like its a tooth out so may get it properly checked. Did yours run okay? Or better once sorted?

 

To be honest it ran fine a little low on compression that side due to the timing, get the belt checked and sorted if necessary. If that's your cause hopefully you'll be fine.

 

Thanks for the advice. I will get it checked and report back.