andrewgti

My Impreza Type R 1999 has been throwing a check engine light for a while now on and off. Sometimes if I don't drive the car for a while say maybe a few a weeks, I can then drive it then for a couple of days before the engine light appears again but once it starts coming on it will then start staying on longer and longer the more times that I drive it. It's starts off where it will go out once the car the is up to temperature and I won't see it again then until the car is parked up and has time to get to the cold start stage again and the same process will happen again. With the light gradually staying on longer and longer each day that I drive it as I said above. The car will also idle a bit lumpy when its warm but will never stall and doesn't hamper the performance in anyway.

Any way I decided to do a diagnostic check on the car today by connecting the 2 black plugs under the steering wheel to see if I could figure out what fault codes were stored. I think there are 2 different ones 12 - Starter signal and may be 23 - Mass Air Flow Circuit but if someone with a bit of knowledge on how to read codes this way can watch the video below and see what they think would be great.



Thanks in Advance

**jay**

iTrader: (1)

I'm reading it as 22 knock sensor one code

Vxr2010

Have the 99 plates not got an obd port ? If so a cheap code reader for 15£ would be a good idea , is the car running ok ? Mafs don't normally show a code but try some carb cleaner on it , they are a weakness and were not that expensive , I would hope knock sensors are not too much either , does the battery charge and run ok voltage wise ?

Neil XR

iTrader: (1)

reading code 22

knock sensor

andrewgti

It does have a diagnostic port but I bought a cheap odII scanner which doesn't fit so I think because of its age and the fact its an import it must be using a different type of port possibly from reading on the forums it is ODB1 but I could be wrong with that. I wish that I could find a scanner that would work though because that would be so much easier.

andrewgti

Thanks mate it could well be code 22. I will do some research in to the symptons of a failing knock sensor and see if it matches the issues that I get.

**jay**

iTrader: (1)

Failing knock sensors causes all sorts of terible running timing gets pulled all over the place, make sure the new one is torqued up properly when fitting its very easy to knacker a new one.

andrewgti

Thanks for the information Jay. I will get a new sensor ordered soon and will be careful when replacing it not break it by over tightening or as I have seen on other forums by lining it up incorrectly.