Subaru Outback Forums banner

1 - 20 of 24 Posts

·
Registered
Joined
·
1,573 Posts
Discussion Starter #1
anyone have any idea of why the oxy sensors for late OBs are so cursedly expensive? or whether it's possible with a little cut-n-solder of wires to adapt a generic one? are they wideband sensors or what? i normally do these every few tuneups as a PM item, but at $200ish....???!!!!!

grazie.

bw
 

·
Registered
Joined
·
15 Posts
I'm curious as to why you are changing the O2 sensor.

I've been having problems with very jumpy acceleration and I've replaced - not just about everything - but actually everything except the O2 sensor. It was suggested on this board that O2 sensor may be my problem but I've been hesitent to spend the money.

Well, Today I just ordered a front and rear O2 sensors in hopes this may be the fix. I have a '97 outback and got the parts from carpartsteam.com. Total delivered price was $158.
 

·
Registered
Joined
·
1,573 Posts
Discussion Starter #3
2 reasons: symptoms and computer diagnosis. o2 sensors go bad in terms of driveabilitylong before they're so far out of range that they set a code in the computer. common symptoms include jerky on/off throttle transitions and flat spot just off idle. when i did the one on my Jeep (figured it was time, at 170K+ on orig....), i experienced about a 113% improvment in light-throttle driveability.

i have an erratic "check engine" light on dash of my 02 OBS (2.5MT), which is getting more towards being on all the time. i previously had the guys at local Firestone (whose work i trust) hook it up to analyzer and they got code indicating o2 sensor. took in to dlr, the light had gone off by then and they said couldn't find anything to fix. once it's on full time, i'll take it back in since i shd still be under warrantly for emissions related components like this. if they can't/won't fix it, may just do it myself and see if i can get SOA to reimburse me for parts (yeah, right....).

thx for info on source; that's less than i was looking at for front sensor alone. if you don't have one of the dedicated oxy sensor removal sockets, it's well worth the $7-12....location of sensors tends to be inaccessible with normal wrenches. this turns multi-hour cussin and spittin job into easy 15-20 min one.
 

·
Registered
Joined
·
1,573 Posts
Discussion Starter #5
most otto partz stores shd have....K-D Tools and Lisle Tools are 2 of the big automotive-specialty-tool mfgrs, so if the locals aint got it, find the nearest place that carries their line. or try northernautoparts.com , 800 831-0884. good outfit i've dealt with for years, and they carry the entire Lisle line; socket is Lisle part #12100, $10.99 (iwent and dug out catalog to check address). be sure to route wires on new one EXACTLY the way old one was so they don't get fried by heat.

this may not completely solve yr problem, but i'd be surprised if it doesn't improve drivability significantly. keep me posted, as i may get tired of waiting for dealer to deal with it. not sure, but it might be a good idea to reset the computer after you change em?? i'm not sure on how to do but i've seen several threads mentioning, so someone does

bw
 

·
Super Moderator
Joined
·
6,009 Posts
Hmm...if I bought that wrench would this be described as an "easy" DIY job?
I'm always looking for ways to extend the lifespan of my best friend.

(Keep in mind that I DIY'd my rear strut replacement, so if you think this is easier than that -which I can't imagine it wouldn't be- then I shouldn't really have a problem)
 

·
Registered
Joined
·
25 Posts
O2 Sensors

The CEL came on in my OB at 58,000 (just under warranty). The dealer pulled the code, determined the Cat was bad and replaced it. Then five miles from the dealer the CEL came on again. The dealer pulled the code, this time determined both O2 sensors were bad and replaced them. No problems since (knock on wood).
 

·
Registered
Joined
·
15 Posts
I changed both O2 sensors on my '97 OB last night. The O2 sensor tool was a must for the rear one but I couldn't use it on the front. Anyway, don't want to jinx myself but the car ran excellent right after the change. A huge improvement. It felt like it was November of 1997 and I was just driving off the lot.

I hope this lasts. It's been 1 1/2 years, 2 Subaru dealers, 1 mechanic, with this problem. I truly hope this was the fix!
 

·
Registered
Joined
·
15 Posts
Well I guess I spoke too soon. This morning driving about 65mph I felt the car suddenly feel sluggish. Pulling off from the next stop light the car was acting up again. I guess the O2 sensors didnt' do the trick and this was just another instance of the car temporarily working well after a engine reset. Anyone have an engine reset would make the car run well but only for a short time?


Thanks.
 

·
Registered
Joined
·
17 Posts
That's a bummer.....

Well I'm not sure what else you had replaced but have you checked your fuel filters and or the fuel sending unit? I just had mine replaced thats why I'm throwing this out there...
 

·
Registered
Joined
·
21 Posts
I don't know what you guys are smoking but just replacing your O2S is not going to solve your problems. All the O2S does is monitor the amount of oxygen in the exhaust and adjust Long Term and Short Term Fuel Trims to keep the engine emissions below 1.5 times the legal limit. If you want it to run like new, do a simple tune up, it should help.
 

·
Registered
Joined
·
1,573 Posts
Discussion Starter #12
I don't know what you guys are smoking but just replacing your O2S is not going to solve your problems. .

and we're all glad to meet you too..... :)


you're absolutely correct that just willy-nilly replacing parts to solve a problem isn't wise. however, go back and read the rest of the thread...*****i normally do these every few tuneups as a PM item****


If you want it to run like new, do a simple tune up, it should help

tuneup on modern EFI car involves, depending on how thorough you want to be, valve adjustment if needed (ie, mech lifters), compression or leakdown test, possibly plug and fuel filter replacement if they're due, plug wires ditto, dist cap n rotor if it still has distrib, oil and filter change (this can affect way it runs), replacement of the air filter (or cleaning if you have aK&N etc), checking fuel pressure at rail and for vac leaks, off-engine injector cleaning if it's been over 100K, possible cleaning of TB and/or IAC valve, timing belt if it's overdue, and oxy sensor replacement.

All the O2S does is monitor the amount of oxygen in the exhaust and adjust Long Term and Short Term Fuel Trims to keep the engine emissions below 1.5 times the legal limit.

i respectfully disagree. it doesn't do anything to long term fuel trim unless you have another problem that the computer is having to "learn" to compensate for. and narrow-band oxy sensors as fitted on all production cars i'm aware of only have capability to measure within a very narrow range on either side of stoichiometric ratio (abt 14:1 air to fuel mass)....maybe from 12.7:1 to abt 15.5:1....so they by definition keep mixture a **** of a lot closer to stoichiometric than 1.5x the legal emissions limit, IF they're working correctly.

my comments on oxy sensor losing ability to measure accurately long before computer sets a CEL are based on info from Bosch tech rep, in response to Q of whether they were just hyping product when they recommended changing sensor every othetr tune-up, and have been confirmed by significantly noticeable driveability improvement on every vehicle i've done it on, either as part of a tuneup (where effect could be masked by improvement in all areas) or where i've only done the oxy sensor by itself.

altho i've certainly been shown full of guano on many issues, i stick to my opinion that changing em every few tuneups will aid driveability/emissions/mileage, even if there's no CEL present. i promise i won't come to your town and force you to change yours. even if i've been smoking something especially powerful...:D
 

·
Registered
Joined
·
9 Posts
Change o2 sensor as PM ?

I have had 4 O2 sensors in my car since manufactured
(orig replaced 3 times, 1st under recall, later when recall replacement failed and it's replacement failed and got CEL and stalling).

Per Autozone website, "Most manufacturers recommend you should change your oxygen sensor every 30,000 to 50,000 miles." At 50k mi, maybe I should be on my 2nd sensor, not my 4th ! Found another parts distributor with a bit more info on the topic :

http://www.autohausaz.com/honda-auto-parts/honda-emissions-oxygen-sensors.html

Per this website, they say newer cars should replace preventively after 100k,
but I"m on my 4th. They do point to the many reasons a sensor might need replacement sooner, but I don't know why I am on # 4, and what I can do to prevent this from being replaced ever 10k instead of 100k mi. Any ideas ?

Also, at one point the OB was stalling due to this. Failing emission test is one thing (I never did) but stalling and leaving you stranded is another.
 

·
Registered
Joined
·
44 Posts
so in response to the fellow saying the special socket didn't work on the front O2 sensor, what did work? simple crescent?

is there a torque spec on it? I need to pull mine and clean it, any suggestions on cleaning these?? someone said isopropyl alcohol only??

thanks!!!
 

·
Registered
Joined
·
4,804 Posts
You don't need the special socket. You do need a 22mm or 7/8" wrench, ideally 6 pt. If you unplug the sensor connector, then you can feed that through the wrench before wrenching. Having the exhaust a little warm when doing this seems to help.
 

·
Registered
Joined
·
125 Posts
I'd also recommend that you soak the sensor with some PB Blaster and let it soak for an hour or so.......the last thing you want to happen is have a frozen sensor rip the threads out of the bung.

If it is frozen try the Blaster soak again followed by some raps on the connection to help the rust solvent penetrate....last resort woud be to heat up the bung to cherry red with a torch.........OR take it to a shop that can do that.

Good luck....these can be a cake walk OR the job from ****.
 

·
Registered
Joined
·
26 Posts
Tool for Oxygen Sensor job

I bought a flare end wrench for this job. While the six-point wrenches are ideal, I couldn't get the closed box over the wire harness. This tool did the trick without having to worry about the wrench slipping off and damaging the bolt edges. It did need a couple whacks with a mallet to break the old sensor free (even after soaking with penetrating oil), especially since there's not much room to work in there. I believe the size you need will be 7/8 (22mm).
 

Attachments

1 - 20 of 24 Posts
About this Discussion
23 Replies
16 Participants
mvbaums
Subaru Outback Forums
Welcome to the Subaru Outback Owners Forum, we have tons of information about your Subaru Outback, from a Subaru Outback Wiki to customer reviews.
Full Forum Listing
Top