Hey all

Recently purchased my first subaru impreza, engine management light was on, plugged it in and it come up with a misfire on cylinders 2 and 4.

Since then I changed the coil pack, ht leads, new plugs and new fuel filter. With no joy whatsoever. The car misfires while idling but seems to be worse under load. I noticed when clearing the code it takes a few days to come back up sometimes sooner, sometimes longer. I've heard people mention the maf sensor but I cannot find it on my car or if it has one.

I'm at a loss any info or ideas would be grateful

Thanks

 

It should be after your air filter, try spraying with cleaner.

 

I had a look where it would be if it had the standard air box, but it has an induction kit (k&n) and is nowhere to be seen. No sensors at all going to the induction kit.

 

Could be a couple of other things too like
A knackered O2 sensor or
Knock sensor.

 

Funny you should mention the O2 sensor, when I first plugged it in that come up as well on the fault code list along with the misfire. But I cleared it and hasn't come back back since its just the misfire showing up now. Knock sensor could be next on my list.

 

I've had a similar problem with mine, tried all the things that you've tried and nothing fixed the problem until I bought a new knock sensor and it seems ok now, been fine for a few months. If that didn't work I was going to buy a new 02 sensor but they are quite pricey so I was leaving that one till last. You won't find a MAF on a GX btw, they have a MAP sensor instead, don't ask me what the difference is lol

 

Yeah I'm gonna take it off tomorrow and get one ordered, I thought they didn't have a maf sensor just needed someone to clear that up lol fingers crossed this works. If not I may have to look at compression tests and dig deeper. I'll keep you updated cheers guys

 

Just a small update guys, I ran some tests with the multimeter on the knock sensor, and it was totally dead nothing at all. Looks like it was that hopefully! I have one on order so should be here in a few days. Fingers crossed

 

Where did you get it from, mine was just a fleabay job

 

Similar problem on the wife's N/A wagon - O2 sensor was faulty.

Mick

 

Snap mate, autoecosse which is the main subaru dealer where I'm from wanted £83 for the genuine part, eBay wanted from £10 to £60, I went for the genuine part at £60 just to be sure. Hopefully this will fix it.

 

Think the O2 sensor is my next option if this fails, it did come up at one point. But hasn't been back on for a few months. The exhaust is blowing slightly as well from middle cat. That's why I thought it was on

 

How's the car running now then? I had another idea for you, I used to always run mine on regular unleaded with it not being an import car or anything. I recently put super unleaded in by mistake and I noticed the difference straight away. The car pulled a Away more smoothly and didn't hesitate. It seems to go through the gears better too. Maybe using super unleaded or V Power night do your car some good.