OFFROADSUBARUS.COM

Go Back   OFFROADSUBARUS.COM > Technical Forums > Under the Bonnet/Hood

Notices

Reply
Thread Tools Display Modes
  #1  
Unread 17th December 2017, 03:20 PM
scalman scalman is offline
Senior Member
 
Join Date: Dec 2017
Location: Lithuania
Year: 2001
Model: Outback '01, 2.5 NA , VDC
Transmission: 4eat
Posts: 767
scalman is on a distinguished road
Cool EJ251 loss power, stall fault catalyst/O2/Air flow/IACV

so things continue as this or similar from when i bought car.its about for 2 yrs now. i changed spark plugs, wires, petrol filter , LPG filter , air , oil changing as supose too and diff oils too. but from beggining i have some kind of power loss or lagging when wanna accelerate from stop. sometimes it goes fast and sometimes it thinks 1,2,3 seconds just then moves.

i was reading what could cause that and such , was cleaning all intake parts and valves that can be cleaned there.

i am getting just P0420 code what says bank1 error. so it kinda O2 sensor , but does front sensor can cause power loss , stall sometimes from no reason and lag in acceleration ? its sounds more like air flow mass sesnor , or IACV . and then could that be bad catalyst. but again would catalyst cause all those symptoms ?

so i cleand IACV maybe 3 month ago. it was not so bad , but i cleaned it anyways and other valves and sensors too that people say in net could cause suchs problems. but just today my call stall in middle road. but then i stopped fast , put on P start engine again and it went as if nothing happens. i had stall engine before too before cleaning that IACV.

so whats about that air flow mass sensor then ? i found as forester ppl talked about that this one can sause power loss and lagging with moving car.

and error says its kinda front O2 problem. but thats kinda not very much as O2 does .

or could it be both sensor like air flow and IACV ?

whats else then .

and more important is there any simple ways to test those parts for fault ? i heard to test catalyst you remove front O2 sensor and try drive as that. if power comes back then its catalyst fault. can it be true this test?

when i wanna car go quick and floor to metal car sometimes doesnt even move for like couple seconds. then when i want to overtake other cars i need to really floor it pedal full. and then it does something ... i thought it might just gearbox kinda slugish but then i read all those people have similar problems too.

thx all .
Reply With Quote
  #2  
Unread 17th December 2017, 03:50 PM
jf1sf5's Avatar
jf1sf5 jf1sf5 is offline
Senior Member
 
Join Date: Aug 2012
Location: Geneva, Switzerland
Posts: 1,567
jf1sf5 is on a distinguished road
Default

The symptoms you describe can be defective O2 sensors. It normally only happens when the engine is hot, after 10-20 km of driving.
__________________
Subversive...
Reply With Quote
  #3  
Unread 17th December 2017, 03:59 PM
scalman scalman is offline
Senior Member
 
Join Date: Dec 2017
Location: Lithuania
Year: 2001
Model: Outback '01, 2.5 NA , VDC
Transmission: 4eat
Posts: 767
scalman is on a distinguished road
Default

so loss power , ohh and forgot to mention raised fuel usage too, those are not from air flow/ sensor ? or from IACV ? if car stall in midle of road from nowhere and then starts again and goes like its nothing . all this making one little front O2 ? you think so ?
i know my code says its P0420 but that can be caused by many problems still isnt it ? not just O2 itself
i think it can be cold engine too. its varies . sometimes its drives better and sometimes just worse. in mountains when i was in austria i was about 2200m above sea level and i was going up hills i felt like im driving fiat 500 classic model. just car felt like it doesnt have power at all. all cars where passing me. and i was flooring pedal all time. nothing more i could do there.
i just wanna be as much as i can sure about what i need to change because i no have money to change all those things.
Reply With Quote
  #4  
Unread 17th December 2017, 04:13 PM
Kevin's Avatar
Kevin Kevin is offline
Administrator
 
Join Date: Jul 2008
Location: Sydney, Oz
Year: MY'03
Model: Forester
Transmission: A/T
Posts: 4,422
Kevin is on a distinguished road
Default

Yes, loss of power and raised fuel usage can be caused by a bad O2 sensor - the car runs rich when the O2 sensor is bad.
__________________
MY'03 Foz AT XS with centre lock-up
MY'10 Triton AT GLX-R 2.5 DiD
www.subaruclub.com.au
Reply With Quote
  #5  
Unread 17th December 2017, 04:21 PM
scalman scalman is offline
Senior Member
 
Join Date: Dec 2017
Location: Lithuania
Year: 2001
Model: Outback '01, 2.5 NA , VDC
Transmission: 4eat
Posts: 767
scalman is on a distinguished road
Default

so that would be first thing you would check ? couple local forester guys where telling that air flow could do those too.
any way to test it ? can i disconnect O2 and run or remove it and test some. or its no way to test it ? that P0420 sometimes stays off when i reset it , sometimes comes back faster.
and you talking about front O2 sensor yes ? i mean i have just 2 them. and rear one doesnt seams to impact on anything kinda.
and problem is not same all times. sometimes i t can run just fine. then next day it feels like crap for some time.
so its not clogged catalyst then ?
Reply With Quote
  #6  
Unread 17th December 2017, 04:26 PM
Kevin's Avatar
Kevin Kevin is offline
Administrator
 
Join Date: Jul 2008
Location: Sydney, Oz
Year: MY'03
Model: Forester
Transmission: A/T
Posts: 4,422
Kevin is on a distinguished road
Default

Yes, front O2 sensor. I'll see if I can find a test.
__________________
MY'03 Foz AT XS with centre lock-up
MY'10 Triton AT GLX-R 2.5 DiD
www.subaruclub.com.au
Reply With Quote
  #7  
Unread 17th December 2017, 04:56 PM
jf1sf5's Avatar
jf1sf5 jf1sf5 is offline
Senior Member
 
Join Date: Aug 2012
Location: Geneva, Switzerland
Posts: 1,567
jf1sf5 is on a distinguished road
Default

I'm 99% sure its the O2 sensor but don't blame me if I'm wrong !
__________________
Subversive...
Reply With Quote
  #8  
Unread 17th December 2017, 05:17 PM
scalman scalman is offline
Senior Member
 
Join Date: Dec 2017
Location: Lithuania
Year: 2001
Model: Outback '01, 2.5 NA , VDC
Transmission: 4eat
Posts: 767
scalman is on a distinguished road
Default

i would want to believe you . because its not cheap sensor. what if i cnage just one front and left rear one old. they wont have problems then because they will be different makers or anything. ? what im finding is some Bosch o2 or Denso sensors here. and NGK ones. thats what i think are better quality ones at least.
some say if you change best to change both of them.
Reply With Quote
  #9  
Unread 17th December 2017, 05:25 PM
jf1sf5's Avatar
jf1sf5 jf1sf5 is offline
Senior Member
 
Join Date: Aug 2012
Location: Geneva, Switzerland
Posts: 1,567
jf1sf5 is on a distinguished road
Default

Pull your O2 sensor and buy a new one same make. But you shouldn't have any problems if its a different make or if you have an old and a new one. My Forester only has one O2 sensor though.
__________________
Subversive...
Reply With Quote
  #10  
Unread 17th December 2017, 09:28 PM
Kevin's Avatar
Kevin Kevin is offline
Administrator
 
Join Date: Jul 2008
Location: Sydney, Oz
Year: MY'03
Model: Forester
Transmission: A/T
Posts: 4,422
Kevin is on a distinguished road
Default

A little research indicates it could in fact be your rear O2 sensor (or your cat) so have a read of these threads at SFORG and especially the "$5 fix":

http://www.subaruforester.org/vbulle...-input-741217/

http://www.subaruforester.org/vbulle...-again-728945/

http://www.subaruforester.org/vbulle...e-back-742521/

http://www.subaruforester.org/vbulle...-thread-42085/
__________________
MY'03 Foz AT XS with centre lock-up
MY'10 Triton AT GLX-R 2.5 DiD
www.subaruclub.com.au
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


All times are GMT -3. The time now is 02:46 AM.


Powered by vBulletin®
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.