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WRX Rookie 10-12-2013 08:21 PM

Engine Misfire Code Help!!
Hey guys, so i got a tough situation (long story so prepare to read)
Just so you guys know what i did so far.....
i have a 2002 wrx and my CEL turned on, first it came up at P0301 P0303 P0304 (cylinders 1,3,and 4) (now remember this)
so i did a basic spark plug change thinking it would work, it turned off cause i disconnected the battery, got some mean backfires, thought it worked, a while later it came back on, same codes, so i tried to swap coil packs 4 and 2, to see if it was the coil packs, of course, codes came back on, now this time it was cylinders 1, 2, and 4, should be 1, 2, 3 right? then i just cleared it with a scanner, now it gets weird, it just turned on again recently after a month and now its P0303, and only that, just cylinder 3

[B]Occasions it turns on[/B]
now when it turns on, im just randomly driving/cruising, no high RPMS, no WOT, once when im just at idle at my friends house, you dont feel it misfire

When i drive hard, not too hard, i treat my WRX like a baby <3, and get out my car you smell gas
I run kinda rich i guess you can say, shitty MPG ~150 full tank
Rough idle but not too rough, like little jitters, if you focus you can feel it
No loss in power
No boost loss, still a strong 17psi

Its not my MAF its good(live data stream on a scanner)
Its not my sensors (live data stream from scanner)
Cam timing but only if its more than one misfire?!
Coilpacks or Wires?
Valves getting stuck open?
Fuel filter?
Fuel pump?
EGR valve?
Vacuum leak?
Boost leak? (probably not if i still have 17psi)
Need a re-tune?
Compression loss?

Im not looking to waste a lot of time myself trying to figure this out taking manifolds off, getting compression checks, wasting money on parts or new tunes if it wont work and hoping someone can give me some feedback from the symptoms and occasions listed to help me knock out some possiblities and narrow down the cause

Any feedback is appreciated! Thanks!

06_hawk_eye 10-12-2013 08:26 PM

Bad gas? Did it sit for a long time ?

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WRX Rookie 10-12-2013 08:29 PM

nope, daily driver, always run premium

06_hawk_eye 10-12-2013 08:39 PM

You running a tune? I saw you have bov in your parts list. Try putting stock one on and see how it goes

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WRX Rookie 10-12-2013 08:49 PM

yeah the guy i bought it from said it was a stage 2 tune but you really think its the BOV?

06_hawk_eye 10-12-2013 09:09 PM

That's fully atmospheric right? Not recirc. It would be a good step to eliminate from the cause. You will notice a huge difference between shifts with a stock bpv.

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06_hawk_eye 10-12-2013 09:16 PM

I've had a check engine light a couple times as miss in 1. Always after getting gas. Only has happened 2 times in a year. I've always just cleared it and went on with my life.. Clear the code when you replace the bpv and see if it comes back on.

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WRX Rookie 10-12-2013 09:40 PM

i'll have to find one on craigslist or something cause i dont have the stock BOV, but would it make me run rich and have non-noticable misfires if i have a Blitz? i dont want to be a pain but how would having an aftermarket BPV cause misfires?

06_hawk_eye 10-12-2013 09:57 PM

It might not be causing your problem but its not good for your car. It'll be easier to diag the car when the right parts are on it

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WRX Rookie 10-12-2013 10:03 PM

are all atmoshpere BPVs bad and wrx's should have recirc? can i get another aftermarket recirculating one instead?

06_hawk_eye 10-12-2013 10:19 PM

Yeah that'll do just fine as long as it is a recirc man

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WRX Rookie 10-12-2013 11:02 PM

Cool thanks, had no idea, what do you think are some good recirculating BPVs other than stock?

boo-key 10-12-2013 11:09 PM

549 Attachment(s)
Forge and Cobb.

06_hawk_eye 10-12-2013 11:10 PM

A Cobb xle I think is the name I run the stock one. But I'm only at 16-17psi. Check out Cobb. Sell that blitz and get a good Cobb

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WRX Rookie 10-13-2013 01:30 AM

I wouldn't have to get it re-tunedif I get a recirc BPV would I?

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