CEL P0301 what should i do ?

[MPREZIV]

Originally Posted by Dean

Oil of any kind, animal, vegetable, or miniral can FU a MAF.

Most of the K&N related MAF isues I have heard of have been related to recharged ones where the asshats didn't read and/or follow the instructions and tried to do a recharge in < hour, and/or used more than the reccomended amount of oil. The filters have to be completely dry before you oil them and most idiots won't wait that long.

That's the thing tho, with Nissans anyway, is that for some reason, they are SUPER picky, and I've seen TONS that crap out with no oil from the filter on them. As soon as you drop the new, factory oiled filter in, you get a CEL. Maximas and Sentras are notorious for this!

Kind of Apples and Oranges, Nissan and Subaru, but IF the Subi MAF is nearly as sensitive, I could see it being the problem. I'd like to think it may have shown up sooner tho...

[sperry]

Originally Posted by MPREZIV

That's the thing tho, with Nissans anyway, is that for some reason, they are SUPER picky, and I've seen TONS that crap out with no oil from the filter on them. As soon as you drop the new, factory oiled filter in, you get a CEL. Maximas and Sentras are notorious for this!

Kind of Apples and Oranges, Nissan and Subaru, but IF the Subi MAF is nearly as sensitive, I could see it being the problem. I'd like to think it may have shown up sooner tho...

But Alex isn't seeing a MAF CEL, he's got a misfire. I'm more apt to blame the problem on the higher air-flow leaning out the car and messing up the plugs over 11k miles than to blame it on the element's oil.

The issue w/ the K&N element was more of an aside as to why I wouldn't re-install that particular intake, even if he were to get the car re-tuned for it.

[A1337STI]

When i remoded my Intake i added aditional heat shielding (i have spare sheet metal if you want it dean, although since i paid like $3 ish , and i'm trying to avoid driving as much as possible, its cheaper for you to buy some, then to pick it up in tahoe - though if Brian ends up here for work maybe i can hand it off and it will make it to a meet?)

I have not yet recharged my air filter. i was just thinking the filter was about due. But now its about due to be pulled off for the stock intake. [tonight if i can borrow tools / if not , way soon]

Sucks to be wrong.
its even shittier to be wrong with a broken car

(to bad that i LOVE the motor/turbo noises with that intake\ though not enough for motor damage) After my car is fixed Maybe i'll hunt down a different filter/ intake (Only when i can get EM + Tuning directly after)

I really hope Sperry is right.

is it likely that i've cuased permanent motor damage ?

[MikeK]

Maybe your intake temperature is too low

[Kevin M]

Originally Posted by A1337STI

is it likely that i've cuased permanent motor damage ?

Very unlikely. Like I said, a million things can cause misfires. I used to get them in my RS after I did the Exedy flywheel because the ECU couldn't accept that revs were suppose to rise and fall that fast off-idle. So, replacing plugs and your stock airbox *should* fix the issue.

[sperry]

Originally Posted by BAN SUVS

Very unlikely. Like I said, a million things can cause misfires. I used to get them in my RS after I did the Exedy flywheel because the ECU couldn't accept that revs were suppose to rise and fall that fast off-idle. So, replacing plugs and your stock airbox *should* fix the issue.

A few misfires isn't (shouldn't) gonna break anything. I've plain old unplugged the fuel intector signal wires while testing my motor for issues. Car idles like a pile, but it's not gonna break the motor unless you go out and romp on it, and even then as long as it's not detonating, it's not the end of the world.

It actually may be something as simple as a loose connection on the spark plug or fuel injector... any chance you bumped anything while working on the intake?

[A1337STI]

Yes there's a chance i bumped into things. i had a hard time sliding my new heat shield in and out. although my hands and the shield were only the ABS side of the K&N shield. the only items i could see that i had to worry about was the ABS brake lines. i can't rule out that i did not elbow or bump into something.

I'm not sure where my fuel injector is or what it looks like. maybe i'll bug Ansel to give my engine area a visual once over.

Maybe Mike, i really don't know

I did do 3 things directly before seeing the CEL. Remodded, filled up at a different gas station, reset the cu
i did read on howstuffworks.com how the MAF sensor works. according to the interweb, new model subarus , heat up a wire to a given tempature, and then it reports to the ecu how much voltage is required to heat up that wire to what ever given temp they use. so if your intake system cools that wire down more then the stock system, it reports a higher voltage. if your intake system does not cool down the wire as much as stock , then it reports a lower voltage. (more reasoning why everyone was correct that changing the intake requires a tune, or going back to stock)

[Kevin M]

Your understanding of the MAF is essentially correct. There are "hot wire" and "hot film" style MAFs, as well as old school "flapper door" types.

[A1337STI]

flapper door? sheez even air flow is confusing
and i'm up to about 50 miles now since the CEL clear, the CEL has not returned (i'm sure the problem is still there though)

[MPREZIV]

Originally Posted by sperry

But Alex isn't seeing a MAF CEL, he's got a misfire. I'm more apt to blame the problem on the higher air-flow leaning out the car and messing up the plugs over 11k miles than to blame it on the element's oil.

The issue w/ the K&N element was more of an aside as to why I wouldn't re-install that particular intake, even if he were to get the car re-tuned for it.

That's kinda what I was saying, however unclear...

I would def. say it's more likely to be the lean condition, than the filter oil taking out the MAF, since it took 11k to show up.

I think I thought the part I was supposed to type and typed the part I was supposed to think.

[A1337STI]

400 miles since i got my CEL cleared at autozone and it hasn't come back ?!? when i took my car into subaru i was at about 300 miles, and the service guy (Jerry) said he's seen a number of subarus throw a few CELs due to bad gas. He said the ecu can retarded the timing so much you get a misfire. he said if it threw the CEL just to come right back in and i won't need an appointment since i came down once.

I did get gas from a different station (american gas in tahoe) twice before i got the CEL. the last time being about 10 or so miles before the first CEL ...

[Kevin M]

"Bad gas" usually means "we don't know what happened, here's a random meaningless explanation for you."

[JonnydaJibba]

They might as well have told you there was a tiny unicorn poking holes in your exhaust and shitting in your filters.

[sperry]

Actually, STI's are pretty sensitive to gas quality. Ask MattR about a particular 76 station in Livermore... we left that place making popcorn under the hood.

[cody]

Originally Posted by JonnydaJibba

They might as well have told you there was a tiny unicorn poking holes in your exhaust and shitting in your filters.

They should have put it on an oscilloscope to check if your ignition system is working correctly. You can spot a bad plug/coil that way.

[tysonK]

Originally Posted by sperry

Actually, STI's are pretty sensitive to gas quality. Ask MattR about a particular 76 station in Livermore... we left that place making popcorn under the hood.

That was awlful.

[A1337STI]

hmmmf. I'm still confused. it does seem to be running a bit smoother now (400 miles later and fill ups at different gas stations)

I took the engine up to 6K repeatedly going to and back from truckee since then, no CEL. I'll make sure to get my 30K service early , chalk it up to bad gas , unless there are other recomendations someone may have ???

Oh and lucky me ! I ran over a nail or something on my way down , or while in carson. when i left the subaru dealership my back end got very fishy on me so i stopped to check tire pressure. Driver side Rear was flat i pumped it up to 38 , drove across town and it was down to 32. drove up to tahoe and it was still at 28 at my house. i tried some fix a flat stuff, and refilled it to 36. but the leak got worse and it went all the way flat. So i'm back on my snow tires for a week or two (had to pick a friend up @ truckee that day)

hopefully i can stop wrecking my subaru for a week or two here.
[as per suggestions i'm off the k&N too]

[A1337STI]

CEL came back. went in today. bad coil pack. they have to order it, should come in friday.

[cody]

Now you're getting somewhere.

[MPREZIV]

Simple fix, and covered under warranty! Can't beat that!

[cody]

If you really miss the K&N, sell it and buy this.

Actually I was wondering how much quieter is the intake now that you have gone back to stock (minus the silencer)? I assume power feels the same?

[A1337STI]

new coil pack installed. idles a bit smoother. car seems happier (and i am too)

Nice find Cody!, i saw the one for the legacy GT 2.5 and asked in the subaru parts department if they had one for the sti but they did not.
Its much quieter back on the stock intake box, and the first plastic air peice + an elbow. but the car is still fun to drive but all the great turbo noise / whine is gone (honestly i hate the stock lack of noise in comparison) i may put the K&N back on for winter / after the rallyx events are all done.

[cody]

That elbow holds back a lot of noise. Most people don't bother with it. But since you're rallying, you may want to keep it.

[A1337STI]

It came back. taking the car in thursday, don't feel like taking the day off of work to sit at subaru (again) , and they don't have free loaners anymore (or so they said) so i think i'm doing a $20 a day rental , so i can get groceries after i get paid (tomorrow) then i'll drop off the rental cuase driving in tahoe, over the 4th of july weekend is useless.

Arg no car for the extended weekend ... lame


with how my car luck is going, i'm thinking i'll be buying the extended warentee pretty soon .

[sperry]

Originally Posted by A1337STI

with how my car luck is going, i'm thinking i'll be buying the extended warentee pretty soon .

Which is going to be a massive waste of money if you continue to rally-cross it. I don't care how stock the car is, you're gonna break something big and expensive and Subaru is going to (rightfully) deny the warranty due to you driving it so hard.