Welcome to the North American Subaru Impreza Owners Club Thursday August 27, 2015
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
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 > 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.
* Registered users of the site do not see these ads.
Thread Tools Display Modes
Old 03-02-2011, 11:34 AM   #1
Scooby Newbie
Member#: 246673
Join Date: May 2010
Location: Central NY
Default Misfire code P0302

My '06 2.5i set a P0302 misfire code. I cleared the codes with a scan tool and its been code free for 200 miles but the car seems to be running rougher than normal at idle and during acceleration from a stop.

My plug wires and coil all check out within spec per the service manual but with 125k miles could they be worn out and still test okay?
BDZ is offline   Reply With Quote
Old 03-02-2011, 03:49 PM   #2
Scooby Specialist
Member#: 80465
Join Date: Jan 2005
Chapter/Region: RMIC
Location: Aurora, CO
2001 2.5RS
Black Diamond Pearl


The wires could be, don't know about the coil. Have you checked the plugs themselves? Do eet.
yarrgh is offline   Reply With Quote
Old 03-03-2011, 09:24 AM   #3
Scooby Newbie
Member#: 246673
Join Date: May 2010
Location: Central NY

Plugs have less than 20k miles on them. Replaced at ~109k with Tbelt and waterpump.

Wires and coil pack ohmed out per service manual spec with no visible cracks or degraded insulation. I misted an alcohol/water mix under the hood to look for evidence of a bad wire but was unable to detect any arcing.
BDZ is offline   Reply With Quote
Old 03-03-2011, 01:17 PM   #4
Scooby Specialist
Member#: 114177
Join Date: May 2006
Chapter/Region: RMIC
Location: SLC utah
2004 Impreza 2.5rs
70 Datsun Fairlady


a misfire is a hard thing to track down. I'm having the same misfire and I've been working on mine for a while. I would swap you plugs/ wires/ injectors and see if it follows the change. If not, find a place with a OBD II reader that can do freeze data and find out when the misfire is happening. It can be a number of other things like, bad cat or O2 sensor, timing, knock sensor, valve lash, or burnt valve but usually those will cause multiple codes. I have cams and a LW flywheel and crank pulley so i always thought that was my problem but it may have just been masking my actually misfire. After i did my 6-speed swap and put in a heavier flywheel all the misfires went a way but the p0302, so i may have had an actual misfire the whole time and didn't realize it.

Last edited by aclver1; 03-03-2011 at 01:33 PM.
aclver1 is offline   Reply With Quote

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
P0302 misfire code 03 spec r1 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 8 12-14-2010 12:40 PM
#2 Misfire CEL Code P0302 SkunkBug02 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 19 09-15-2009 12:47 PM
Code P0302 misfire #2 Impwrxza Vancouver Impreza Club Forum -- VIC 4 06-21-2009 09:04 PM
Misfires- P0301 P0302 P0303 P0304 AndyHidley Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 3 11-30-2001 01:18 AM
Check Engine Code P0302, "#2 Misfire" hillman Legacy Forum 5 06-26-2001 03:14 PM

All times are GMT -4. The time now is 09:38 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2015 Axivo Inc.
Copyright ©1999 - 2015, North American Subaru Impreza Owners Club, Inc.