Keeping it simple, I think my oxygen sensor is stuffed. I tried to test it today with a multimeter but i couldnt get any reading from it. I know its supposed to be between 0.2-0.8volts but i couldnt find any. I dont know if thats because its actually broken or its my inept ability with a multimeter. Anyway is there some definate way to tell if its broken? If it is broken is it easy to replace? Is it worth getting a genuine replacement or go non-genuine? To be honest i didnt know they made non-genuines but went to mitsu today who said they were $70 but that a non-genuine would be cheaper. Which leads me to my last question but where would you get a non-genuine from? bursons or something?

- Repco have some Generic one's for about $60 or something.
- With the 02 sensors it is imperitive - absolutely imperitive that they are at operating temperature to get an accurate reading. Go and rape your car for 5 mins and it will be working sweet.
- Now hears the tricky part...
Our Magnas, like many other cars use a type of fuel injection system known as closed loop monitoring (or something like that). Umm, gotta go i'll finish off this message later. I promise :D

well mate i dunno which mitsubishi gave u a quote of $70 because northern mitsu quoted me $470.... i ended up getting the NGK version from burson's for $150....

I paid $60 off a mechanic mate so i'm assuming thats trade price, and he installed it for me, only took him no more than 10 minutes

yeh i know about the closed loop stuff. Reading from the Air flow sensor and air temp sensor tell the ecu how much fuel to put in, the O2 sensor then sends a message to the ecu whether its running rich or lean and to adjust fuel mix as appropriate. Then continuesly runs the loop adjusting. And at start up the O2 sensor is not giving off any readings which is one of the reasons your engine runs rich when you start up. Theres a whole lot more to it but thats the basics. Standard process control. Anyway the reason i first thought that my O2 sensor has gone bad is that the engine is running rich all the time and my fuel effeciency has jumped out to 14L/100kms. But as stated in previous post, i dont know if its the O2 sensor or my lack of ability with a multimeter or something else is wrong.

Did mine this afternoon. TR 2.6l.

I went to Repco and bought the o2 sensor.

It's the single wire one and I didn't need the flange (but got it anyway). $84. Denso.

What you'll need.
22mm Open ended spanner,
12 and 10 mm sockets,
CRC/WD40/RP7 or alike,
Couple of screwdrivers (small flat and jeweler type set),
Mallet or hammer and wood drift,
Crimping tool,

To do was hell easy. Disconnect battery, disconnect o2 sensor from main wiring loom by lifting small tab with screwdriver and pulling apart.
Undo the heat sheild bolts.
Spray WD40 (or alike) onto o2 sensor where it joins the mainifold.
Let sit for an hour.
Take 22mm spanner and belt anticlock-wise to loosen o2 sensor. I had the engine warm to do this but be carefull not to burn yourself :redface:
Once out, take the end off the connect by using a small screwdriver inserting it into the connector and lifting the plastic tab. Pull apart.
Now the hard part - undo the connector from the wire (or buy a new connector, but hey it wasn't available anywhere I went).
Cut the new o2 sensor wire to length - connect to the new connector with crimping tool.
Screw back into manifold and tighten.
Attach heat sheild.
Reconnect o2 sensor.

Test drive.

how did you know the O2 sensor was stuffed? What symptoms did your car show?

Cool you got the jist of it. Bad fuel economy can mean a couple of things. One might be the 02 sensor. Another might be an air leak of such. Or a faulty air sensor. Or some other things. Anyone who has a TR/S should get a Gregories workshop manual as they help out a lot. Sorry I cant help out anymore but there's food for thought.

I'll grab my manual out tonight and throw a few points onto the table for discussion, I've gotta head off to work or I'd do it now.

EVERYONE I spoke to said the fuel economy I was getting was stupid. Like I mean I get 12.9l/100km out of the work BA 5.4l XR8, the Magna was getting 14 on a bad day 12 on a good with the same style of driving. :nuts:

The thing lacked power espically when hot. Whe I read that they o2 sensor in the Magna only turned on when hot it was a no brainer. 12 year old o2 sensor out new one in.

Car is yet to return any figures but normally I would have filled up twice as much by now :D

I figured for $80 I couldn't go wrong.

thats something i wanted to hear ShaginWagon, did u buy it from bursons or was it a genuine mitsu part? Is there any way that you can get the O2 sensor to turn on when its cold or not?

Like I said earlier

"I went to Repco and bought the o2 sensor.

It's the single wire one and I didn't need the flange (but got it anyway). $84. Denso."

We don't have a Bursons store here in WA.

Also mention the year and model of the car. I would get the one with the flange just in case your car (mines a 92 TR SE Wagon August build 2.6l EFI) is different.

Economy is 12L per 100km with air con. Still not great but a lot better. I still get the occasional bog down lack of power but I think thats related to a crack I found in the exhaust header.

Guess what I'm fixing next month :bowrofl:

currently im getting about 13.5L/100kms. I have the same type car in a 2.6L TR EFI but i have extractors. Will the same O2 sensor fit? and i think that my O2 sensor got stuffed when the guy put the extractors in.

I figure the extractors have the same connector otherwise a different type of o2 sensor would have had to be fitted.

To be sure get the flange thrown in. $2 extra and worth it to save hassles.

Is there much benifit in those extractors ? Some guy on here is selling a set of RPW's and since my exhaust manifold is gone...

RPW dont make extractors for the 4cylinder magna except the 2.4L im pretty sure. I got Hi-Tech extractors which i find have given a bit better torque in the mid to upper range but i think have probably taken a little from the low end. BTW i got an NGK O2 sensor from bursons yesterday for $58 and was extremely easy to install. Will soon find out if that improves the fuel effeciency.