I found the cause of my Check Engine

"E30Joe drives a Subaru" (325joe)
02/26/2014 at 19:18 • Filed to: None

If you were not aware, !!!error: Indecipherable SUB-paragraph formatting!!! .

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I pulled the code and it's a P0301 (Misfire on cylinder #1).

I hope its a plug, not a coil, or a bent valve, broken spring, bad injector, or anything of the sort. Please just be a spark plug for the love of god.

DISCUSSION (18)

HammerheadFistpunch > E30Joe drives a Subaru
02/26/2014 at 19:20

I had that on my 05 forester xt

bad injector. These injectors are pretty sensitive to crap gas. Good news is that its not too expensive and really easy to change an injector.

jkm7680 > E30Joe drives a Subaru
02/26/2014 at 19:21

Hope it's something cheap and easy enough to fix. My car just loves to eff with me by throwing random warning lights at me, and then having them disappear next time I turn the car on.

Zipppy, Mazdurp builder, Probeski owner and former ricerboy > E30Joe drives a Subaru
02/26/2014 at 19:21

does it run rough at all?

E30Joe drives a Subaru > Zipppy, Mazdurp builder, Probeski owner and former ricerboy
02/26/2014 at 19:23

Only under 20-50% throttle. Anything above half all the way to WOT is like nothing is wrong. Idle is fine. When the throttle is completely closed it misfires occasionally only in gear.

E30Joe drives a Subaru > HammerheadFistpunch
02/26/2014 at 19:24

I've only filled with 93 from BP but I can't say the same for the previous owner. I have a warranty from the dealer I just don't want my car there. They are not very intelligent.

desertdog5051 > E30Joe drives a Subaru
02/26/2014 at 19:26

Many times a bad plug will cause a coil to fail (trust me on this). If you have individual coils, pull the plug too.

Zipppy, Mazdurp builder, Probeski owner and former ricerboy > E30Joe drives a Subaru
02/26/2014 at 19:27

My father's 330xi had a constant misfire a couple weeks ago, turned out to be a bad coil.

HammerheadFistpunch > E30Joe drives a Subaru
02/26/2014 at 19:29

yeah I bought mine at 45k miles and within 2000 miles it happened, previous owner I'm sure.

Here is my experience on it when it happened

All you have to do to replace an injector is relieve the fuel pressure (I can't recall how to do it, but its something like disconnecting the fuel pump wire, cranking over briefly, then disconnect the battery and holding a button to remove any excess power in the system) then you just remove one screw holding a small bracket, pull of the injector harness (plug) and yank that sucker outta there. Installation is opposite, but you don't need to do the fuel pressure stuff to install. Just tighten the bracket, plugin the injector and fire her up.

E30Joe drives a Subaru > Zipppy, Mazdurp builder, Probeski owner and former ricerboy
02/26/2014 at 19:54

I just cleared the code and drove around for awhile and it hasn't returned. I expect it's return within a day.

Jeremy H formerly Kalakaboooom > E30Joe drives a Subaru
02/26/2014 at 20:13

My 300 had a misfire over Christmas break. Went through the list of easy things, did plugs, coils, and then fuel injector relay and fuel injector. Turned out to be my fuel injector

E30Joe drives a Subaru > Jeremy H formerly Kalakaboooom
02/26/2014 at 20:49

I cleared it and drove 5-10 miles and it didn't come back. Hopefully it stays that way and was just something to do with the -10 degree weather we have been having.

Jeremy H formerly Kalakaboooom > E30Joe drives a Subaru
02/26/2014 at 21:01

A bit of seafoam could also help that cel stay away as well

E30Joe drives a Subaru > Jeremy H formerly Kalakaboooom
02/26/2014 at 21:05

I'm going to get the correct plugs (I'm assuming the current ones are not gapped right) and do a little ghetto tune up with some seafoam and all that

Jeremy H formerly Kalakaboooom > E30Joe drives a Subaru
02/26/2014 at 21:10

When you get some time you might want to check your coils as well, while might weren't the cause of my misfire it's good I checked I had 3 coils burnt up. But if plugs and some seafoam don't clear it up the injector might be toast. Could try using new seals. Spit ballin here I'm running on fumes

E30Joe drives a Subaru > Jeremy H formerly Kalakaboooom
02/26/2014 at 21:12

Could be a number of things. So far the issue hasn't returned but WHEN it does I'm going to start going through ignition stuff.

Jeremy H formerly Kalakaboooom > E30Joe drives a Subaru
02/27/2014 at 08:12

True. Just more of the if it ain't broke don't fix it

megalomaniac > E30Joe drives a Subaru
02/27/2014 at 12:58

Slow down before you jump to conclusions, when you hear hoof beats think Horses not Zebras.

You need to look at a Missfire as a single cylinder crank-no start, which fall under your basic triage of Spark, Fuel, Compression. Confirm that it has spark then move onto confirm that it has fuel (add adquete pressure), then look for the oddball like compression (Pretty rare, I was a mechanic for 8 years and only saw one car with compression loss and it slipped the timing belt 180*).

Again, Confirm that you have spark at the coil, then spark at the plug (bench test it, mount the plug in the coil and ground the threads). 90% of Missfires are Coils or Plugs.

E30Joe drives a Subaru > megalomaniac
02/27/2014 at 13:14

I haven't done anything to remedy it, I wouldn't start going crazy with taking the head apart looking for bent valves or broken springs. I'm buying 4 spark plugs that are gapped correctly and if that doesn't fix it I'm going to actually find out whats causing it instead of throwing parts at it