Well awhile ago i had that idle problem and the mechanic said that the ecu reported an error with the O2 sensor. Prior to this the engine warning light would come on here and there. So he cleared the carputer and the check engine light dissappeared for a long time. Now it's back and my fuel economy lately has been pretty ****e (450kms to a tank :(). This sounds like the O2 sensor right? I havn't replaced it in 2 years though i dunno how long they are suppose to last. So i know you can go to autobarn/repco and pick up a new O2 sensor, but how hard is it to install?

Thanks for any help :).

450km's to a tank is normal.......

i get 200-300 a tank.

450 aint bad for an auto and sedan (presuming tank smaller)

tr-envys super tr usually gets 550 a tank as he says..

someone on here posted up how to remove the sensor. try usin search. ive read it before. its easy.

tr-envys super tr usually gets 550 a tank as he says...
lol super tr.
I used to get 600+ (in freeway driving, but at least 5-550 normal driving) and going from that down to 450 is degrading, it's happened gradually, i'll do a search on the o2 sensor, but if anyone finds it before me, post up a link :). Ill let ya all know if it improves fuel economy or not :).

Remove the LH side cover from under the console
The cable comes up through the floor, white plug.

Make sure car is cold, jack up car, support with stands, get under, pull cable through the floor with the grommet.

Spray some CRC or similar on the area around the sensor

Get RING spanner to fit, remove, then install in reverse order

One reason for an 02 sensor failing so quickly is a lot of mechanics and backyard mechanics use silicone based sealant in the engine, ie rocker covers, air intake etc
This is all bad. Only use sealents that state safe for Catalytic Converters and 02 sensors

Remove the LH side cover from under the console
The cable comes up through the floor, white plug.

Make sure car is cold, jack up car, support with stands, get under, pull cable through the floor with the grommet.

Spray some CRC or similar on the area around the sensor

Get RING spanner to fit, remove, then install in reverse order

One reason for an 02 sensor failing so quickly is a lot of mechanics and backyard mechanics use silicone based sealant in the engine, ie rocker covers, air intake etc
This is all bad. Only use sealents that state safe for Catalytic Converters and 02 sensors
Thanks heaps for that mal! You are a legend when it comes to 2nd gens, should open your own workshop :P.

Remove the LH side cover from under the console
The cable comes up through the floor, white plug.

Make sure car is cold, jack up car, support with stands, get under, pull cable through the floor with the grommet.

Spray some CRC or similar on the area around the sensor

Get RING spanner to fit, remove, then install in reverse order

One reason for an 02 sensor failing so quickly is a lot of mechanics and backyard mechanics use silicone based sealant in the engine, ie rocker covers, air intake etc
This is all bad. Only use sealents that state safe for Catalytic Converters and 02 sensors

Mal what are you on about???? were talking about a Gen2 not a Gen1 aren't we?

To replace Oxygen sensor in a Gen2,
1. Open Bonnet
2. O2 sensor is on the front of the exhaust manifold, follow wire back and unclip 02 sensor plug from engine wiring loom (plug is over front engine mount)
3. Undo 5, 12mm bolts from manifold heat shield and carefully remove heatshield from O2 sensor wire.
4. With a 21 or 22mm SPANNER unscrew the O2 sensor, you can't use a socket unless you cut the sensor wire

to refit reverse steps.
when fitting the new O2 sensor be careful not to damage the wire or plug.

Mal what are you on about???? were talking about a Gen2 not a Gen1 aren't we?

To replace Oxygen sensor in a Gen2,
1. Open Bonnet
2. O2 sensor is on the front of the exhaust manifold, follow wire back and unclip 02 sensor plug from engine wiring loom (plug is over front engine mount)
3. Undo 5, 12mm bolts from manifold heat shield and carefully remove heatshield from O2 sensor wire.
4. With a 21 or 22mm SPANNER unscrew the O2 sensor, you can't use a socket unless you cut the sensor wire

to refit reverse steps.
when fitting the new O2 sensor be careful not to damage the wire or plug.
lol now i'm confused, i THINK mal is talking about the actual metal box thingy (mine is in near my ECU) and you are talking about the actual sensor. It's the sensor that goes ****ty right? If it's that easy i'll it myself, mals way sounded too hard for me :P.

I tried to get my o2 sensor off and its stuck like sh :rant: t to my favourite shoes. Does heating the manifold help, 2nd gen 4 cyl.

I haven't touched mine yet but i've read that it's easier on a hot exhaust.

Hello TR-Envy,

Try looking at these links from a US 1st generation Diamante. It might help in kowing what to look for. You'll need a speacial socket that has a grove cut out of the side of the socket to get around the wiring.

Hope this helps
TG

http://img166.echo.cx/img166/3403/scan00043rm.jpg

http://img166.echo.cx/img166/6997/10000185nc.jpg

http://img166.echo.cx/img166/7876/10000191nw.jpg

http://img166.echo.cx/img166/5108/10000232xm.jpg

http://img166.echo.cx/img166/3007/10000280ma.jpg

http://img166.echo.cx/img166/9219/10000270ry.jpg

http://img166.echo.cx/img166/9996/10000291fz.jpg

sorry but those pics are no good. the oxy sensor on the 4 cyls are placed on the exhaust manifold. The one in the pics is placed after the cat converter

have you tried putting some RP7 around the sensor to try and loosen it Marty?

I've decided i really dont know what i'm doing, so i'm just gonna get my mechanic to do it when he reco's my engine in july/august :).

dude its easy as. I did mine in like 10 minutes at most. its sitting in the manifold right in front of you when you open your hood up. To find it open the hood and look straight down. There should be a single wire comming out of the manifold region right in the middle, thats it. You just disconect the wire, unscrew it from the manifold, screw the new one in and connect the new wire. Theres only one wire so its impossible to stuff up. Easy.

OK, i think i understand now,
Madmagna is talking about the V6 right? where it's near the cat, and on the 4's it's on the front (if it's what i think it is i dont blame it for being faulty, the wire is all frayed where it connects, has been since i bought it.

My Haynes repair manual suggests removing the O2 sensor while the manifold is hot.

The reasoning is that the manifold contracts when it cools and therefore would make it hard to remove O2 sensor.

Has anyone had major difficulty getting one out when cold, or anyone tried the hot way (and not got burnt :) )

yeh did mine when it was hot.

lick the manifold once its hot too. its good.

hahaha no that is not a good idea, if your o2 sensor is playing up your a/f mixture would be faulty due to it and you may have lost power; have you noticed this???

I rang around today to get some prices for a replacement O2 sensor. Heres what I found (dearest to cheapest).

Genuine Mitsubishi From Dealer - $478.00
Repco Direct Fit - $220.00
Repco Universal - $170.00
Autobarn Universal - $129.00
Bursons Universal - $105.00 (mentioned possibly a cheaper one at around $70-80)
Regional Auto Supplies -$101.55

Imlachs (Melbourne Recyclers) - $99.00 (Recycled)

Is it better to go for the genuine/direct fit one or is it easy enough to adapt the universal fit type? Was told they come with instructions to fit, mainly to do with either using 1,2,3 or 4 wires.

i thought i read someone on here got theirs for about $60ish?... hmm

i havent looked into ths yet, but i wil be soon

pseudomorphous got it from repco down here in vic for 70-80 bucks i think. Hey does anyone wanna help me change mine on saturday? :P.

Bursons for i think it was $78 with a can of wd40. As the 4 cylinder is only the single wire sensor so is cheap.

Bursons for i think it was $78 with a can of wd40. As the 4 cylinder is only the single wire sensor so is cheap.
Cool there's a bursons in berwick just round the corner from me, i'll pick one up during this week and someone can help me install it at the show and shine on saturday :D.

No idea what sort is on my '91 V6 Verada. Need to get them car ramps this weekend to have a look, and also test the sensor directly to make sure it isnt the wiring.

I found second hand one at a sydney wreckers for $60 (including postage). Not sure whether to get that or not. I am looking around for a complete vehicle that I can wreck myself at the moment. If I can find one then I may have another O2 sensor in 6 months time anyway.

I am guessing physical forces on these things are really not the reason they stop working. Being that they are subjected to 300 degree + heat day in day out I am assuming they are generally sturdy things? Maybe someone else might have some comments on this?

On the O2 sensor topic, can anyone tell me about the actual electrical nature of the sensor? ie what the voltage levels directly relate to? I know they measure the air fuel ratio but I wanted to know what voltage they output at correct ratio. What is the voltage change in respect to actual air mixture?

Well I got hold of some jackstands to get the car high enough to get to my O2 sensor. As it was too hard to budge I covered it in WD40 and left it for a while.

While I was waiting I decided to go looking for the spot where the wires went from underneath the car into the passenger compartment on their way to the ECU. Took the panel off the left hand side of the centre console and bingo there was the connecting harness plain as day.

While I was waiting for mr WD40 to work I thought I would reconnect the multimeter and doubly make sure of its reading. By the way, for those of you who have the 6G72 engine the O2 sensor is a 4 wire sensor. (The yellow wire from the sensor in my case was the one feeding the ECU with the green being earthed). Connected up the multimeter and I got a good reading from it!

So after all that my O2 sensor is good to go. ($100 saved), but now I have to look elsewhere to find the problem. I am pretty sure there is a sensor issue somewhere. I am just about to test every other sensor I can and document reading etc.