Subaru Forester Owners Forum banner

1 - 12 of 12 Posts

·
Registered
2005 Subaru Forester auto 230k
Joined
·
6 Posts
Discussion Starter #1
Original title before thread merge:
2005 - Sputtering when cold, shuddering/stuttering when warm in low rpms? - SOLVED!
2005 Forester w/ 225k and automatic trans. For months it's been sputtering while accelerating during the first few minutes while the engine warms up, and if I try and push it too hard (i.e. give it too much throttle) it will stall out. When I say "sputtering" I mean the exhaust makes a sputtering sound and the car will loose power momentarily as though the throttle is being let off, a few times per second during the low RPMs of each gear. Then it's 30 min of fine highway driving to work. Getting off the interstate and back into traffic, now the engine's warm and instead of sputtering in low rpms it "shudders," by which I mean it looses power momentarily a few times each second but it's more pronounced and the whole car jerks, w/o the sputtering sound, similar to trying to drive a manual transmission car in a high gear at too low a speed. I could make it go away by just giving it some gas to get it out of the lower rpm range and it would drive fine.

Fast forward to yesterday, we had a big snow w/ high winds & low temps. Car is un-garaged. I let it warm up for a few minutes, but the sputtering was way worse and it would just stall out instead of accelerate. It also stalls during idle intermittently. It's basically undrivable.

Any help would be greatly appreciated!!
 

·
Registered
2005 Subaru Forester auto 230k
Joined
·
6 Posts
Discussion Starter #3
Just ran them - P0031, P0134 and P0031P; I had the P0134 a while back and replaced the downstream 02 sensor, but that didn't take care of it. I'd planned on replacing the upstream one but never got around to it. The P0031 is new.
 

·
Registered
2001 Forester
Joined
·
1,891 Posts
P0031is the upstream sensor. And that one affects A/F ratio hence the sputtering and dieing.

Sent from my Pixel XL using Tapatalk
 

·
Registered
2005 Subaru Forester auto 230k
Joined
·
6 Posts
Discussion Starter #7
2005 subaru forester w/ 320k. A few months back, my sputtering/shuttering problem threw the codes P0031, P0134. I replaced the upstream o2 sensor and it appeared to fix the issue.

Now the sputtering at low RPMs is back and the car is again nearly undriveable. This time it's throwing P0420 (ineff. cat) and P0304 (misfire in cyl4).

Any thoughts? Could the misfire be causing the P0420 or vise versa? Do I need to bite the bullet and spend more than the car is worth on a new cat?

Any help would be greatly appreciated!
 

·
Administrator
2007 Forester Sports XT 4EAT
Joined
·
39,439 Posts
@EBK565869 there's no need to start a new thread, when you're continuing the troubleshooting started in your previous thread. It's better to keep all your troubleshooting in one thread. Your threads have been merged.

Also...
For the best forum experience, we recommend completing your "Account Details". The optional information you enter there will display when members click "About" in your forum profile. You can also create a custom "Signature" that will display every time you make a forum post. The optional additional information you provide could mean getting forum member replies, or not.

Note that your thread could be closed until you fill out your Public Profile"!
Bobby...

['07 FSXT Member Journal] ['03 X Member Journal]
 

·
Registered
2001 Forester
Joined
·
1,891 Posts
The last time I had p0420 on my 2001 was around 100,000 miles (now 221,000 miles) just outside the epa warranty. I paid the $1200 for new cat and the issue has never returned.

Sent from my Pixel XL using Tapatalk
 

·
Registered
2005 Subaru Forester auto 230k
Joined
·
6 Posts
Discussion Starter #10
Well, I reset the CPU (ie unhooked and reconnected the battery) and let it idle for 10 minutes to reset the idle control. The CEL/cruise came back on and now it’s throwing P0301, P0302, and P0304. And it won’t turn over now unless I coax it with the gas pedal. Ugh.
 

·
Registered
2010 Forester Premium 2.5x Automatic 4sp
Joined
·
223 Posts
I had the very same issue with my 2010 Forest at around 145k.
Replaced my sparkplugs , wires and coils and it was solved.
Keep in mind all that was OEM. 10 years and 145k for oem wires and coils I think is ok.
 

·
Registered
2005 Subaru Forester auto 230k
Joined
·
6 Posts
Discussion Starter #12
I had the very same issue with my 2010 Forest at around 145k.
Replaced my sparkplugs , wires and coils and it was solved.
Keep in mind all that was OEM. 10 years and 145k for oem wires and coils I think is ok.
Ok. I'll try new plugs/wires/coils. That's definitely less expensive than a new cat.
Thanks for the info!
 
1 - 12 of 12 Posts
Top