Welcome to the North American Subaru Impreza Owners Club Saturday March 30, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

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.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 03-05-2008, 06:50 PM   #1
Susie's Suby
Scooby Newbie
 
Member#: 21370
Join Date: Jul 2002
Chapter/Region: MAIC
Location: In the #24 Chevy--I mean Subie
Vehicle:
01 Impreza RS 2.5
Blew-ridge Pearl

Default Help me!!!

I am ready to drive this car off a cliff.
We have an 01 2.5RS, the engine started to have a bad misfire. I replaced plugs and wires, no improvement. Took it to a dealer, they found a cracked y-pipe, also showed codes for misfires on 2,3,4 cyls, cat sysytem efficiency below threshold (p0420), evap emission control system malfunction (p0440),
and evap system vent control low imput. We replaced the y-pipe and cats, now runs even worse. If revs go below 4000, the engine just about dies. While we were waiting for cats to come in, the shop put a straight pipe in, and the car ran fine. They installed the cats today and its bad again. Does anyone have any ideas why this would happen?
Mike
* Registered users of the site do not see these ads.
Susie's Suby is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 03-05-2008, 07:23 PM   #2
novacivic
Scooby Specialist
 
Member#: 117980
Join Date: Jun 2006
Chapter/Region: NESIC
Location: Rochester, NH
Vehicle:
2005 sti
wr blue

Default

maybe o2 sensor or bad coil
novacivic is offline   Reply With Quote
Old 03-05-2008, 08:06 PM   #3
Susie's Suby
Scooby Newbie
 
Member#: 21370
Join Date: Jul 2002
Chapter/Region: MAIC
Location: In the #24 Chevy--I mean Subie
Vehicle:
01 Impreza RS 2.5
Blew-ridge Pearl

Default

Is there any way to test the coils? and if they were bad, would they still work at high rpm's?
Mike
Susie's Suby is offline   Reply With Quote
Old 03-05-2008, 08:24 PM   #4
Subyroo2.5
Scooby Specialist
 
Member#: 168129
Join Date: Jan 2008
Chapter/Region: SCIC
Location: High Desert
Vehicle:
2013 WRX
WRBP

Default

Do you have a digital multimeter? you can use that to check the resistance of the coils but I dont know what the spec is............and no the higher the rpm the more load is put on the ignition system...
Subyroo2.5 is offline   Reply With Quote
Old 03-05-2008, 08:56 PM   #5
subtoy
Scooby Newbie
 
Member#: 173384
Join Date: Mar 2008
Default

Try spraying some water on the coil,if it sparks it is no good.
Does it run bad all the time?
Could have jumped time if it runs rough all the time.
May have to do a leakdown test just to make sure cylinders are ok.
subtoy is offline   Reply With Quote
Old 03-05-2008, 09:22 PM   #6
Susie's Suby
Scooby Newbie
 
Member#: 21370
Join Date: Jul 2002
Chapter/Region: MAIC
Location: In the #24 Chevy--I mean Subie
Vehicle:
01 Impreza RS 2.5
Blew-ridge Pearl

Default

It runs strong over 4000 rpm's, but wants to die below, while you are driving. It will idle about 10-15 seconds smoothly, the drop to below 500 rpms and shake. If you give it the gas it will pick up revs immediately, but then repeat the low idling and shaking. It is very frustrating.
Mike
Susie's Suby is offline   Reply With Quote
Old 03-06-2008, 08:59 AM   #7
bobko
Scooby Newbie
 
Member#: 64646
Join Date: Jun 2004
Location: Northern Virginia
Vehicle:
1995 Legacy wagon
Green

Default

Quote:
Originally Posted by Susie's Suby View Post
It runs strong over 4000 rpm's, but wants to die below, while you are driving. It will idle about 10-15 seconds smoothly, the drop to below 500 rpms and shake. If you give it the gas it will pick up revs immediately, but then repeat the low idling and shaking. It is very frustrating.
Mike
Could be a vacuum leak. If you can, try to listen under the hood while the engine is running -- a vacuum leak can often be heard as a loud hissing noise. An engine with a vacuum leak (cracked rubber hose, usually) will show exactly the symptoms you describe: smooth and normal at high revs, but stumbles and dies at idle.

You could also check the idle air control valve (IACV or IAV, depending on who you talk to). However, a vacuum leak is the first thing I'd look for and it's easy/cheap to fix.

--Bob
bobko is offline   Reply With Quote
Old 03-06-2008, 12:44 PM   #8
Susie's Suby
Scooby Newbie
 
Member#: 21370
Join Date: Jul 2002
Chapter/Region: MAIC
Location: In the #24 Chevy--I mean Subie
Vehicle:
01 Impreza RS 2.5
Blew-ridge Pearl

Default

Quote:
Originally Posted by bobko View Post
Could be a vacuum leak. If you can, try to listen under the hood while the engine is running -- a vacuum leak can often be heard as a loud hissing noise. An engine with a vacuum leak (cracked rubber hose, usually) will show exactly the symptoms you describe: smooth and normal at high revs, but stumbles and dies at idle.

You could also check the idle air control valve (IACV or IAV, depending on who you talk to). However, a vacuum leak is the first thing I'd look for and it's easy/cheap to fix.

--Bob
Thanks--there *is* a hiss... Are there hoses that aren't in plain sight to check? I sprayed carb cleaner on the ones I could see, but they seemed okay.
Susie's Suby is offline   Reply With Quote
Old 03-06-2008, 05:33 PM   #9
yarrgh
Scooby Specialist
 
Member#: 80465
Join Date: Jan 2005
Chapter/Region: RMIC
Location: Denver
Vehicle:
2001 2.5RS
Black Diamond Pearl

Default

on an 01 RS...hmm....there is a vacuum hose to the pressure regulator and cruise control on the passenger side pointing towards the rear. there is the brake booster on the driver side, also pointing to the rear. you can also try looking at the manifold gaskets for the intake, TB, MAP....ummm. IACV too. maybe check the bolt tightness on some things. also check the hose for the gas tank pressure relief, it's right behind the alternator/PS pump. may have a purple electrical connector.
yarrgh 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
Aaargh! Help me Neek! Help me Tom Cruise! banman Off-Topic 16 09-08-2006 01:50 AM
Help Me, Help Me, Help Me! againstdan Newbies & FAQs 9 11-11-2005 10:26 PM
I need to get a sound clip from ATHF... help me Obi W... I mean help me OT! Asinine Off-Topic 7 03-03-2005 12:33 PM
Help Me! Help Me Please! wrxxxappeal Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 8 05-10-2003 11:14 AM
Help me/Help YOu/Help ME MichiganRS General Forum Archive 7 12-15-2000 08:54 AM

All times are GMT -4. The time now is 12:03 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.