Hey guys,


as written in the title I have the Check Engine Light. The last days I changed oil to Castrol Edge 10-W60 and changed the spark plugs from NGK PFR6G to NGK PFR6B. I also changed the oil filter for another genuine oil filter. I just wanted to go for a little test drive a few minutes ago, started up the car, running at about 1400RPM (bit high isn't it) but I suppose it's normal since the temperature is 0°C . So a few seconds after idling the CEL light started repeatedly blinking. I shut down the car to look after that in the manual. In the cars manual I've read it got something to do with the exhaust cleaning... Anyway, I started the car up again without a CEL. Then I went for a very small drive, a minute after driving off the light started blinking then after about 2 minutes of very soft driving the light was staying on. I turned around, drove back home, another 10 secs later the light started blinking again until another minute later where it started staying on. Then the light was staying on until parking the car back up. And now I'm here asking myself if I've done something wrong. During the spark plug change I've disconnected the battery and the MAF Sensor (as I took out the air filter and its box). Has it got something to do with that?

Car is a 2001 Impreza WRX, no engine mods, only changed to a HKS SSQV BOV.

Thanks for the help

 

reading the code would be a good place to start finding the fault, as its what the ECU is seeing as the fault.

 

Well this could be a bit problematic as I've got no experience with that at all. I've got a cable to plug in at the car ending in a USB port to plug in onto a laptop. Is there any good freeware software I could use for reading out the codes? I also just heard somewhere else on the internet that the problem could be caused by some ignition issues resulting in a faulty fuel/air mixture and then having some fuel/oil dripped in the cat. Suggestion is to turn on the light of the car and then disconnect the minus pole of the battery and let it rest like that for 20 mins...

 

Newage wont reset like a classic, and if the fault is still there then it will only return,

http://www.scoobypedia.co.uk/index.p...gECUCodes#toc2

https://code.google.com/archive/p/ecuexplorer/downloads

 

Ok I'll try my luck with that.

 

Ok, Problem Code is P0304 - Cylinder 4 Misfire Detected

 

Is that coil pack seated right, if so can you swap it with another to see if the fault moves ?
What gap were the new plugs set at ?

 

New plugs had the standard gap of 0.30, I will try to do so in the next few days.

 

0.30 ? not the 0.7 / 0.8 mm that they are supposed to be ?

 

From autodata

 

I suspect the op meant 0.03inch which is 0.8mm

 

yeah I meant that, as in the video I watched it was mentioned as 0.30 inch. I didn't measure it for myself tough, seller in the shop said that you wouldn't need to as they already have the gap. I suspect something with the coil pack, maybe broke a cable as it was freezingly cold outside and cyl #4 is the one really really hard to reach....

 

Seller in the shop said......... take that with a pinch of salt mate, only takes the package to be dropped. take them out and check them yourself, also swap the coil pack over as suggested while your at it

 

Plugs are pre-gapped from the factory,but I would never trust that,always wise to check yourself.

 

My guess is you probably disturbed a connector to an ignition coil.

 

Yeah guess I will measure them again. Will swap coil pack 2 with 4 to see if it is the coil pack. Could it really be the gap of the spark plug?

 

Since you didn't measure them then the gap could be anything so yes it would cause a misfire.

 

Seems to be that this was it. #4 is very hard to reach and seems like while plugging back in I loosened the connector to the ignition coil (swapped spark plugs without disconnecting the ignition coils), while looking at #4 today and wanting to take it out to inspect it I discovered that the connector to the coil just fell off. Well used a bit of contact spray on the plug on the coil, plugged the connector back in, let the car run a bit and everything seems to be fine again.
Just cleared out the fault code of the ECU a few mins ago, lets see how it will work out. Car will get winter tyres put on tomorrow, then I'll be able to properly drive again