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2005 Subaru Impreza WRX
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667 Posts
Discussion Starter · #1 ·
My car is starting to piss me off. Lately, its been throwing a CEL every other day for stupid stuff. Sometimes its a misfire on a random cylinder, sometime its a knock sensor malfunction. Usually, its a misfire.

Initially, I thought it was the plug wires. I had rallitek ones and recently cyl 3 has been misfiring often. I chalked it up to a bad batch or something and chucked them out (4 months after I got them...).

One day, I popped the hood while it was running to check the cable and when to make sure it was secured on the coil pack and got the shock of my life. After it shocked me, it ran perfect.

Now, I have a new coil pack (less than 2k miles on it), new plug wires (less than 100 miles on it) and it keeps on acting odd.

For example, Tuesday: I'll drive it to work, and its fine. Its not running odd, idling weird.. nothing. Its running perfect. No check engine light when I turn it off. I go to leave from work, start it up and the check engine light is on. Whatever, go to leave and hardly will go anywhere. After about 5 minutes, it starts running perfect again.

The CEL is bogging is not consistant. It will happen when its cold/hot/wet/dry. Any idea what it could be?

Incoherant rambling +1. :(
 

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2000 Imp 5 door Sport
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6,269 Posts
if it shocked you it could be that the motor is not grounding out well. add a better ground strap from the motor to the body
 

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Ex-Mooderator
2001 RSTi, 2011 WRX Hatch
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3,278 Posts
if it shocked you it could be that the motor is not grounding out well. add a better ground strap from the motor to the body
Theres in upwards of 20,000+ volts running through that spark plug wire... It will shock you when you pull it off =P especially if you are touching any body part of the car...

20,000 volts will arc a full inch, but some coil packs run much much higher.

-- Dave
 

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Silver 2002 Subaru Impreza RS
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18 Posts
My car ran fine but I was having the occasional misfire and knock sensor codes. Changed the knock sensor and it all went away. Do all that other stuff the previous posters mentioned too.
 

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2005 Subaru Impreza WRX
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667 Posts
Discussion Starter · #7 ·
Have you changed the actual plugs? Do that, also clean air filter, change fuel filter, pcv valve and front o2 sensor, most of those parts are super cheap minus the o2 sensor.
Both air cleaners are a few months old, PCV valve is about a year old. I'll probably be changing my fuel filter this weekend, along with the knock sensor. I cleaned most grounds off a few months ago.

Again, today it was fine going to work. As soon as I go to leave, the CEL comes on and car goes in
mode. After about 10 minutes of driving, its pulling hard and gets out of limp mode. Shut the car off and back on a few times and the CEL goes away.

It might just be the NJ air that it has had to park in lately ;) (I kid)
 

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99' L-WRX wagon
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591 Posts
have you changed the spark plugs? i had this problem with my MY00 Vw passat simple spark plug replacement fixed everything.
 

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95/99 Brighton STi
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2,945 Posts
had very similar symptoms with my L this winter. was throwing the random misfire code and finally one day it gave me a knock sensor malfunction code. grabbed one off my spare motor and swapped it in there and BAM! ran beautifully with no CEL's .... til my rear o2 heater circuit got severed :_sure:

ask someone if you can borrow their knock sensor... quick and easy check
 

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00 It Is What It Is
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31 Posts
whats up guys im new to the site.. i actually had the same problem happen to my 00 rs, and it turned out to be a burnt out plug and a chewed out wire.. after replacing them it worked perfect..
 

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yep. you heard me.
‘18 E63s AMG wagon & 10 Subarus
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6,473 Posts
could just doublecheck and make a DIY grounding kit. at least 1 or 2 grounds just to be safe. its a helpful mod normally so you might as well
 

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1999 Subaru Impreza L Coupe
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281 Posts
Knock sensor malfunction can be a few different things, the wiring has a ground somewhere, the sensor went bad, or it actually is detecting a knock.

My car is sick with the sensor bug (P0325) right now and is going to the Roo doctor Monday. I'll update on the progress at that point.

Its symptoms are similar, the sensor isn't on all the time, but when it is on after a cold startup, the car is in limp mode until it reaches 50mph. After 50mph the car seems to re-evaluate its outlook on life and goes like a raped ape.
 

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2005 Subaru Impreza WRX
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667 Posts
Discussion Starter · #13 ·
My car is limp like an 80 year olds man penis from about 1.5k-3.5k... after that its fine. Its odd, its ONLY when I am leaving from work... wtf?

The day the kock sensor "malfunctioned", anything past half throttle, my car would ping. After my car warmed up, it was fine.

Spark plugs were put in when the new plug wires went in.

I'm getting a gas filter and a knock sensor today.

Knock sensor malfunction can be a few different things, the wiring has a ground somewhere, the sensor went bad, or it actually is detecting a knock.

My car is sick with the sensor bug (P0325) right now and is going to the Roo doctor Monday. I'll update on the progress at that point.

Its symptoms are similar, the sensor isn't on all the time, but when it is on after a cold startup, the car is in limp mode until it reaches 50mph. After 50mph the car seems to re-evaluate its outlook on life and goes like a raped ape.
 

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00 2.5RS BRP
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687 Posts
Check the coil pack/engine grounds and clean those off....

Also take off the intake and give it a nice washdown!
 

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2005 Subaru Impreza WRX
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667 Posts
Discussion Starter · #16 ·
I believe I found out while its only at work when I leave... My car is tilted a bit when I park it. I couldn't figure out why it would only happen in NJ where I work and it be fine all weekend but for some reason it just popped into my head.

So tonight at the drive in, I parked it so the nose was lower than the rear... sure enough, after 2 hours, the CEL pops on when I turn it on.

I drove it home (it was fine after 2 minutes) and turned on/off the car enough times so the CEL was off before parking it tonight on an even surface... if it doesn't pop up than I believe it has something to do with it being parked with either the nose higher than the rear/the nose lower than the rear.
 
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