Jump to content

Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse

- - - - -

how to tell if your O2 sensor is bad?

  • Please log in to reply
6 replies to this topic

#1 Guest_jon61484_*

  • Guests

Posted 26 July 2003 - 11:52 AM

A while back, my gas mileage dropped. It backfires before getting to normal operating temp, and I've checked everything I can think of outside of the sensor. (IE: fixed exhaust leaks, doublechecked things)

now, I unplugged it, and don't see *any* difference in driving.

so, does this mean it's bad? the guy at carquest said "well, it may be alright. you need to get it tested first!"

Do I dish out $27 for a new one today and replace it? or...?

#2 Guest_archemitis_*

  • Guests

Posted 26 July 2003 - 12:00 PM

is this one of those ea81s with the wierd spark plug sensor... or is this mpfi or spfi? i have a bud who made exhaust for his spfi with no o2 sensor and it works great. the tps and maf sensor does most of the work. the o2 just does stuff when you are cruising, which could explain the mileage. the type of fuel delivery could help out the diagnosis

#3 Guest_jon61484_*

  • Guests

Posted 26 July 2003 - 12:51 PM

EA81 carbed 2bbl hitachi. I just bought a new sensor ($24) and I'm going to be installing that shortly.


#4 Guest_Snowman_*

  • Guests

Posted 26 July 2003 - 01:04 PM

Sorry to butt in, but could somebody explain to my how the heck a carbed engine would use an oxygen sensor?

#5 Guest_archemitis_*

  • Guests

Posted 26 July 2003 - 01:27 PM

pre efi emissions. they call it a feedback carb system, i think. does very little

#6 Guest_86 subaru_*

Guest_86 subaru_*
  • Guests

Posted 26 July 2003 - 03:30 PM

mine went bad , when it showed codes , 86 spfi 2wd a/t sedan and another sensor on the motor

#7 Guest_jon61484_*

  • Guests

Posted 26 July 2003 - 08:37 PM

How I could tell immediately that it made a difference was that when starting up (when it's not at normal op temperature yet) it would backfire (like misfiring... but would get worse the colder the temp outside.) when the RPMS would go down (switching gears)

Now it doesn't do that. And it's noticeably smoother on the response and better movement of the tach.

The old one was soooo white, that the fins were completely covered up. Not a whole lot, but enough.

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users