When to replace the O2 sensor? - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > TJ Wrangler Technical Forum > When to replace the O2 sensor?

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineRough Country Jeep Suspension Deals at Rockridge 4WD!Engo winches available at www.rockridge4wd.com! Free shipp

Reply
Unread 11-22-2007, 09:24 PM   #1
Sakislayer
Registered User
1998 TJ Wrangler 
 
Join Date: Jul 2005
Location: Pasadena
Posts: 53
When to replace the O2 sensor?

Guys I have a 98 TJ with 112K+ on it and it runs fine. However, it seem my gas mileage has really started to go into the crapper.... I was wondering if might be partly caused by the O2 sensor?

When should they be replaced? My jeep runs great and doesn't have any check engine lights or codes.... The O2 is the original....

Thanks in advance! OH - and is this a self project? or take it to the shop? I know it just screws out, but given my jeep is 10 years old I'm sure it's in there nice and tight....(ugh)

__________________
[COLOR=Red][SIZE="4"][B]Mike[/B][/SIZE][/COLOR]
[COLOR="SeaGreen"][B]1998 Jeep Wrangler Sahara[/B]

[/COLOR][B]2.5" TeraFlex 2T lift, 1.25" Tera-spacers, 1" Tera Bodylift 32x11.5 BFG ATA's[/B]
Sakislayer is offline   Reply With Quote
Unread 11-22-2007, 11:26 PM   #2
97tjtom
Registered User
1999 TJ Wrangler 
 
Join Date: Jun 2007
Location: minot, nd
Posts: 597
change em. its a do it yourself job with some PB blaster every day a few days before
__________________
Current: 1999 TJ 4.0 5 Speed
Past: 1999 XJ 4.0 Auto, 1993 XJ 4.0 5 Speed, 1997 TJ 4.0 5 Speed, 1994 XJ 4.0 5 Speed, 1993 Cadillac Sedan Deville 4.9L V8, 1991 Isuzu TrooperII 2.8L 5 Speed
97tjtom is offline   Reply With Quote
Unread 11-23-2007, 12:03 AM   #3
MusicMaverick
Registered User
2010 JK Wrangler 
 
Join Date: Sep 2001
Location: Santa Monica, CA
Posts: 1,224
Hey, I'm actually over in North Hollywood. Personally, I'd let it go. When the o2 sensor goes bad, the check engine light will come on. That's what happened with mine when I first bought it. It would come on and off, it failed the smog test because it was giving out faulty readings. As long as you're passing the smog tests and the check engine light is on, your O2 sensor should be fine.

When it DOES go, its a very simple procedure. Since it's a southern car, there shouldn't be much rust, worst case, spray a little WD-40 on it. But mine is a 97' with 70k and it took me all of 15 minutes to unscrew it and replace it.

As for your gas mileage, make sure you use Chevron, Shell, Mobil, etc. Stay away from Amco or those cheap ones, they have a lot of additives in the gas that leave deposits. I had the it professionally burned off of the heads and intake. You can try other things like changing the air filter, spraying out the throttle body, and maybe a bottle of injector cleaner, (I've heard good things about the Lucas Tune-up in a bottle)

Other things, if the wheels aren't balanced, that will cause a decrease in mileage. Same with the oil, if it gets sludgy, it will slow things down.
__________________
Currently:
2010 Wrangler Sport

Past vehicles:
1992 YJ
1997 TJ
MusicMaverick is offline   Reply With Quote
Unread 11-23-2007, 02:25 AM   #4
bigchevyman24
Registered User
2000 WJ 
 
Join Date: Jul 2006
Location: Demopolis, AL
Posts: 1,077
When you get an extra $70...lol...
__________________
CURRENT: 2001 WJ V8 LIMITED - Quadratrac, 60th anniversary, Fat Bob's 2.5/2 lift, HID's, roof rack, 31" Rugged Terrains, 5k lb Curt Hitch

SOLD: 2000 WJ 2WD CONVERTED TO 4X4, 97 TJ ON 35'S, 95 XJ ON 33'S
bigchevyman24 is offline   Reply With Quote
Unread 11-23-2007, 06:09 AM   #5
Davejb
Registered User
2006 LJ Wrangler 
 
Join Date: Dec 2006
Location: New Hampshire
Posts: 513
Quote:
Originally Posted by Sakislayer
Guys I have a 98 TJ with 112K+ on it and it runs fine. However, it seem my gas mileage has really started to go into the crapper.... I was wondering if might be partly caused by the O2 sensor?

When should they be replaced? My jeep runs great and doesn't have any check engine lights or codes.... The O2 is the original....

Thanks in advance! OH - and is this a self project? or take it to the shop? I know it just screws out, but given my jeep is 10 years old I'm sure it's in there nice and tight....(ugh)
o2 sensors are not maintenance items, when they go bad the MIL (check engine light) will come on.
__________________
[B]2006 [COLOR="Red"]Wrangler Unlimited[/COLOR][/B]

[COLOR="Blue"][B]Vote Quimby[/B][/COLOR]
Davejb is offline   Reply With Quote
Unread 11-23-2007, 12:00 PM   #6
TMJeep
Registered User
1998 TJ Wrangler 
 
Join Date: Jun 2004
Location: Glen Allen, VA
Posts: 216
They will not always give you a code saying it is bad. Mine started going bad and it would spit and sputter when I would first start to drive it and about backfire. I replaced it after trying different gas and things like that and has run perfect since. I even took it to get the codes checked and it never had any.

You can buy them from www.oxygensensors.com . They were the cheapest I found and get the OE fit not the universal fit.
__________________
98 Sport TJ 4.0L
[COLOR=darkred]Chile Pepper Red[/COLOR] with Black Dual Tops
Trueflow Air Filter
31" BFG A/T
Cibies headlamps, plus 30 bulbs
other than that pretty much stock for now
TMJeep is offline   Reply With Quote
Unread 11-23-2007, 12:23 PM   #7
HipCheck_1
Registered User
2005 TJ Wrangler 
 
Join Date: Mar 2006
Location: Texas
Posts: 778
Quote:
Originally Posted by TMJeep
They will not always give you a code saying it is bad.
x2. I would change the o2 sensor around 80,000-100,000 miles.
HipCheck_1 is offline   Reply With Quote
Unread 11-23-2007, 01:19 PM   #8
redvett94
Registered User
 
Join Date: Jul 2005
Location: Grayling MI.
Posts: 578
Its recommended to change the O2's at 100000mi because they will get lazy and not toggle quickly. The SES light will only go on if post O2 indicated poor cat. performance or the pre O2 completely dies. You just need to replace the pre O2's for economy & performance. The post O2's only monitor the cat. performance.
__________________
2000 Sport.
redvett94 is offline   Reply With Quote
Unread 11-23-2007, 01:53 PM   #9
fish4life
Registered User
1997 TJ Wrangler 
 
Join Date: Jul 2006
Location: Vancouver
Posts: 1,847
Quote:
Originally Posted by TMJeep
They will not always give you a code saying it is bad. Mine started going bad and it would spit and sputter when I would first start to drive it and about backfire. I replaced it after trying different gas and things like that and has run perfect since. I even took it to get the codes checked and it never had any.

You can buy them from www.oxygensensors.com . They were the cheapest I found and get the OE fit not the universal fit.
Thanks for that link. My O2 sensor has recently gone bad and i DID get a Check Engine light! The engine light went away after a few days, but even now when i scan the codes it still shows up as "upstream oxygen sensor" even with no light.

I was just about to buy a new sensor here, and they want around $100 in Canada for them. Given the strength of the canadian dollar now, That oxygensensor.com site comes to half price of the local shops. Needless to say, i'll be ordering from those guys

btw, my jeep only has 75,000 miles on it, and the thing went
fish4life is offline   Reply With Quote
Unread 11-23-2007, 01:54 PM   #10
Wheelin98TJ
JEEP FREAK
 
Wheelin98TJ's Avatar
1998 TJ Wrangler 
 
Join Date: Apr 2004
Location: , Southeast MI
Posts: 24,398
redvett94 is right on.

Around 100k miles they're to the age where they start to get sluggish. The sensor will still perform within the parameters of the OBD II system and a check engine light will not be set off.

Replacing the upstream sensor(s) can improve your mileage. If you still have the original sensor, there's a real good chance that it will.
Wheelin98TJ is online now   Reply With Quote
Unread 11-23-2007, 03:20 PM   #11
Rocky.ca
Registered User
1997 TJ Wrangler 
 
Join Date: Mar 2007
Location: Canada
Posts: 234
i didnt get any sort of CEL when my 02 sensors kicked the bucket. I picked both the up / down stream sensors at autozone and noticed a considerable increase in gas milage and a complete removal of the "sputtering" that all 4cyl 97 tjs get. its only like $130 for both, just change em out.
__________________
Black 97 TJ SE 4bangin' away.
3" BDS lift
33" A/Ts
Sound System
custom de-milk jugged bumper :D
Rocky.ca is offline   Reply With Quote
Unread 11-23-2007, 04:29 PM   #12
fish4life
Registered User
1997 TJ Wrangler 
 
Join Date: Jul 2006
Location: Vancouver
Posts: 1,847
lol ... yeah ... only like 130 ...
fish4life is offline   Reply With Quote
Unread 11-23-2007, 05:58 PM   #13
Rocky.ca
Registered User
1997 TJ Wrangler 
 
Join Date: Mar 2007
Location: Canada
Posts: 234
oh yeah lol... i forgot, the us dollar took a DIVE. i bought mine w/ my Canadian currency and it seemed like a huge deal to me (i saved about 80 bucks). :P
__________________
Black 97 TJ SE 4bangin' away.
3" BDS lift
33" A/Ts
Sound System
custom de-milk jugged bumper :D
Rocky.ca is offline   Reply With Quote
Unread 11-24-2007, 05:55 AM   #14
Davejb
Registered User
2006 LJ Wrangler 
 
Join Date: Dec 2006
Location: New Hampshire
Posts: 513
Quote:
Originally Posted by Rocky.ca
i didnt get any sort of CEL when my 02 sensors kicked the bucket. I picked both the up / down stream sensors at autozone and noticed a considerable increase in gas milage and a complete removal of the "sputtering" that all 4cyl 97 tjs get. its only like $130 for both, just change em out.
I should have said you will usually get a MIL, my bad. Most of the time they cause something to go out of whack that the computer will pick up, but it may not specifically point to the sensor.
__________________
[B]2006 [COLOR="Red"]Wrangler Unlimited[/COLOR][/B]

[COLOR="Blue"][B]Vote Quimby[/B][/COLOR]
Davejb is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.