Ok so my check engine light goes on, and the cruise control flashes on/off. I took it to the dealership and they said there was a misfire in 3/4 cylinders, they changed the spark plugs and they told me it was fixed. when the car starts up it shakes for 3 seconds and then it idles fine and runs smoothly. the strange thing is that when the Check engine light goes on, it stays on for about 2-3 days, and then it shuts of for 2-3 days. Any thoughts?

 

what mods do you have?

 

We need:
mods
mileage
any changes you made right before problem started
how long has it been going on

 

All I have is an Invidia Catback, the car has 55K miles. it started happening about 6 months ago at like 44K miles. I didn't do anything just before that. The Catback has been on there since I bought the car (NEW). Actually I changed the spark plugs like 8K before that. and they were fried!

 

I had a similar problem with my impreza L, I would replace the wires and when you replace the wires check the terminals on the distribution block/ignition coil.
What happened on my car was that moisture got trapped in the terminal and it got crazy corroded and ended up eating away gold plated covering.

What I did was take my dremel with the wire brush attachment and I got all of the corrosion off, put new plugs on and coated that sucker with dielectric grease.

I would recommend at the least replacing the wires and putting dielectric grease around the rubber. The dielectric grease will not conduct electricity, so don't put it on the contact, but put it around the rubber boot to seal it from outside moisture.

What kind of sparkplugs did you use? I would recommend shelling out the extra for all genuine subaru parts.

Also, have you been running rich or lean? Improper AF mixture can damage plugs, clean your MAF while you're at it.

 

The Imprezas now have a coil on plug system, no plug wires.

 

Thanks I will have to coil's checked out, maybe there is something wrong with them. It smells like its also running a little rich...

 

I would suggest taking it up to LIC in Novato (you'll never regret bringing your car to them) or GST.

 

Ya, take it somewhere and have the cel checked.

 

Call the dealership first and ask them if they ever cleared the codes while it was in there, if they didn't then your most likely just running old codes from before.......

 

Ok thanks for the input everyone...