Welcome to the North American Subaru Impreza Owners Club Sunday August 31, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Service & Maintenance

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 02-14-2005, 01:28 PM   #1
Geoffman72
Scooby Newbie
 
Member#: 27891
Join Date: Oct 2002
Location: Rochester, NY
Vehicle:
2001 Impreza 2.5 RS
Blue Ridge Pearl

Default Ummm, wow thats a lot of check engine codes

So my 01 RS has been acting like an out of tune carbed car in Antarctica. I go to the local autozone to get the codes pulled and they come up with;

Air Metering Sensor
Cylinder misfire on ALL banks
Catalyst inefficiency

Only mods on the car are a exedy lightweight flywheel and sport clutch. The plugs and wires were changed 8,000 miles ago and the vehicle only has 65,xxx on it. I do realize the lightweight flywheels do cause cylinder misfire codes also, but I dont believe this to be the case here.

How it drives;

I do think the cats might be clogged as the car just runs like its got a plug in its butt.
Sometimes it feels semi-ok. but other times it will spit sputter bog down backfire, etc.


Anyone have any ideas before I take it to the dealer?
* Registered users of the site do not see these ads.
Geoffman72 is offline   Reply With Quote
Old 02-14-2005, 01:36 PM   #2
RexyGirl
Scooby Specialist
 
Member#: 63616
Join Date: Jun 2004
Chapter/Region: South East
Location: Mastro Subaru, Sanford FL
Vehicle:
1996 Volvo 850 Turbo
with mods :)

Default

If it is your cat convertor, it is covered under 8/80 warranty.

From they symptoms you described, sounds like that is probably it. To be sure, reset the light and when it comes back on, have it checked again. More than likely only one code will come back..the rest may have been in memory or triggered from the cat convertor.
RexyGirl is offline   Reply With Quote
Old 02-15-2005, 12:00 PM   #3
MrHorspwer
Scooby Specialist
 
Member#: 4063
Join Date: Feb 2001
Chapter/Region: MWSOC
Location: Michigan
Default

Quote:
Only mods on the car are a exedy lightweight flywheel
This may cause your misfire DTC.

The ECM determins if a misfire condition exsists based on the input from the crankshaft position sensor. On a smoothly running engine, a smooth and solid stream of data is received from the crank sensor. When a misfire occurs, a *stutter* is registered by the crank sensor (because there is no firing on a particular cylinder, the crankshaft quickly slows down, then speed back up as the next cylinder fires). This is interperated as a misfire by the ECM.

With a lightweight flywheel, an engine is allowed to rev quicker. The engine may now be able to rev at a rate that is faster than the crank sensors resolution. This will cause the crank sensor to *miss* signals. The ECM will also interperate this as a misfire.

It is very rare to have an engine misfire across all cylinders. Typically, you'll have one or two cylinders that will be your culprit. When you start seeing a scattering of misfire activity that shows no pattern, I'd be willing to bet that your flywheel is the culprit.
MrHorspwer is offline   Reply With Quote
Old 02-16-2005, 01:06 AM   #4
happyparrot
Scooby Newbie
 
Member#: 61896
Join Date: May 2004
Location: Kirkland, Wa.
Vehicle:
1998 2.5rs S/C
RBP

Default

Quote:
Originally Posted by MrHorspwer
This may cause your misfire DTC.

The ECM determins if a misfire condition exsists based on the input from the crankshaft position sensor. On a smoothly running engine, a smooth and solid stream of data is received from the crank sensor. When a misfire occurs, a *stutter* is registered by the crank sensor (because there is no firing on a particular cylinder, the crankshaft quickly slows down, then speed back up as the next cylinder fires). This is interperated as a misfire by the ECM.

With a lightweight flywheel, an engine is allowed to rev quicker. The engine may now be able to rev at a rate that is faster than the crank sensors resolution. This will cause the crank sensor to *miss* signals. The ECM will also interperate this as a misfire.

It is very rare to have an engine misfire across all cylinders. Typically, you'll have one or two cylinders that will be your culprit. When you start seeing a scattering of misfire activity that shows no pattern, I'd be willing to bet that your flywheel is the culprit.
Exacly!
happyparrot is offline   Reply With Quote
Old 02-17-2005, 11:05 PM   #5
BJamerican
Scooby Specialist
 
Member#: 5595
Join Date: Apr 2001
Chapter/Region: HIIC
Location: Honolulu
Vehicle:
2005 Legacy 2.5GT
Satin White Pearl

Default

Well, if your air sensor is failing (error 1), it will in turn cause a misfire since the ECU does not know the actual A/F ratio (error 2). Prolonged misfire, or backfire will in turn damage your catalytic converters (error 3).

Check your MAF or MAP sensor (whichever your car uses) and make sure it's operating within specs. I would get the misfiring problem fixed before you cause even more expensive damage to the catalytic converters.
BJamerican is offline   Reply With Quote
Old 02-17-2005, 11:15 PM   #6
Uncle Scotty
Scooby Guru
 
Member#: 16200
Join Date: Mar 2002
Vehicle:
OK Houston
we have an Uncle

Default

Quote:
Originally Posted by BJamerican
Well, if your air sensor is failing (error 1), it will in turn cause a misfire since the ECU does not know the actual A/F ratio (error 2). Prolonged misfire, or backfire will in turn damage your catalytic converters (error 3).

Check your MAF or MAP sensor (whichever your car uses) and make sure it's operating within specs. I would get the misfiring problem fixed before you cause even more expensive damage to the catalytic converters.


ding...ding....ding.....


...and NOT posting the codes themselves....ie 'Pxxxx' is pointless for us to try to help, really. Some of us have the FSM and can help a great deal if you post the actual code..
Uncle Scotty is offline   Reply With Quote
Old 02-18-2005, 12:07 AM   #7
BJamerican
Scooby Specialist
 
Member#: 5595
Join Date: Apr 2001
Chapter/Region: HIIC
Location: Honolulu
Vehicle:
2005 Legacy 2.5GT
Satin White Pearl

Default

I know the cat inefficiency code is P0420. My car throws that code about twice a year, and my dad's Outback recently started throwing that code randomly. In my case though, I'm guessing that an oxygen sensor is going bad since they have not been replaced in 136,000 miles!
BJamerican is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
need a lot of help w/ check engine codes suby ej25 Tri-State Area Forum 8 01-26-2005 11:02 PM
Help with check engine code Meche 2.5RS Normally Aspirated Powertrain 1 10-10-2001 06:20 PM
Check engine codes Wildman Factory 2.0L Turbo Powertrain 1 07-21-2001 07:04 PM
Check Engine Code P0302, "#2 Misfire" hillman Legacy Forum 5 06-26-2001 03:14 PM
Check engine codes Kruf General Forum Archive 1 12-17-2000 05:46 AM


All times are GMT -4. The time now is 04:28 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.