There seems to be a huge variation in the price of oxygen sensors.
Fuelmiser appear to be expensive, but PE7 and other generic varieties are about half the price...
Cant find info (but haven't looked hard) regarding OEM specs vs replacements.

Therefore my questions are.....
1) Is there really THAT much difference between them (brands) regarding their lifespan?:doubt:
2) Or the return for your $ with a better signal / better fuel efficiency?:noway:
3) Or any brands that will fry the ecu like only a cheap Indonesian DVD can?:rant:
4) Bad or Good experiences of the crowd (Mal?) :slap:
5)...Your thoughts...

Cheers and don't forget to give your Magna a beer for Straya Day...she might have a weird first name (Mitsubishi)...but at least she's Aussie made!
:beer::beer::beer::beer:
Sorry for the emoticons, buts im bored ! :beer:

Just my opinion here.

I used to be a smug b@stard and by oxygen sensors from the U.S. for cheap. Never thought it could be a problem.

Then I mate of mine had issues with one of the Denso oxygen sensors I used to think we're great.

While I don't think I've had an oxygen sensor issue buying them from the U.S. I have found my car runs far better than ever with a genuine oxygen sensor. I'm seeing 11.0/100km in a 3.8 AWD in traffic if I drive right.

So I'm sold. If ever I need a new oxygen sensor it's going to be a genuine one.

Genuine, for an AWD TJ, they're $240.

I still got the original one at 200,000km. Still getting good economy of 7.5L/100km on Hume Hwy and 10L/100km around South-east suburbs of Melbourne.

Not sure who makes the original one but I suspect it is NGK. I once asked the dealer about genuine spark plugs, they were $8ea and he said they were just NGK.

I still got the original one at 200,000km. Still getting good economy of 7.5L/100km on Hume Hwy and 10L/100km around South-east suburbs of Melbourne.

Not sure who makes the original one but I suspect it is NGK. I once asked the dealer about genuine spark plugs, they were $8ea and he said they were just NGK.

Those fuel consumptions are a pretty good indication everything, including the oxygen sensors, are working well.
If your car can give you an instantaneous fuel consumption readout, a bit of a cruise on the open road is a good indication. My TJ averages 7.7L/100 km at 100 kph, over a 150 km trip.

You didn't honestly go into a dealer and ask for "genuine" spark plugs, did you? lol

Lots of original bits on a Magna are sourced from other makers - spark plugs, filters, oil, belts, hoses, seals, light globes, tyres, bearings, glass, and probably more stuff.

Those fuel consumptions are a pretty good indication everything, including the oxygen sensors, are working well.
If your car can give you an instantaneous fuel consumption readout, a bit of a cruise on the open road is a good indication. My TJ averages 7.7L/100 km at 100 kph, over a 150 km trip.

It goes above 8L/100km when on rougher roads like the Newl Hwy.



You didn't honestly go into a dealer and ask for "genuine" spark plugs, did you? lol


I was there getting a belt as it was cheaper than the auto store. Needed some spark plugs as well and thought they might be cheaper to.

Fair enough, no harm in asking.

I still got the original one at 200,000km. Still getting good economy of 7.5L/100km on Hume Hwy and 10L/100km around South-east suburbs of Melbourne.

Mine's on the original sensor, almost at 300,000, and getting similar figures (a bit higher: 7.8~7.9 hwy and 10.5 mixed/suburban, but it is the wagon). I bought the slotted socket intending to replace it but I reckon I'll leave it alone while I'm getting those numbers. So does anybody know the manufacturer of the OEM sensor? Walker, Denso, NTK?

Is it possible to check the oxygen sensor using evoscan? I was looking at some old logs I had and you can see exactly what the sensor is reporting, right down to a 10th of second. Anyone know if this is accurate?

Can't vouch for the accuracy of evoscan readouts, but if it will give a voltage readout that would be a good way to keep an eye on the oxygen sensors.
If evoscan can give you a readout of fuel to air ratios, that would be a good way too.

(Not an evoscan user, so the above may be pure BS.)

The list of things it can log is as long as your arm.

With Evoscan, the items to watch to detect oxygen sensor issues are the long term fuel trims (LTFTs). Once they go more extreme than +/- 10% there's an issue that needs sorting.

The long term fuel trims are rolling averages of the difference between the amount of fuel the ECU is programmed to expect is required and the amount of fuel that is actually required based on the oxygen sensor feedback - positive trims indicate more fuel required and negative trims indicated less fuel required.

There are 3 trims loggable:
- low (aka idle trim; applies to low engine speeds and loads)
- med (moderate engine speeds and loads)
- high (higher engine speeds and loads, usually freeway/highway running).

Oxygen sensors normally read lean as they fail, so the long term trims eventually reach the positive limit (+25% I believe) in this case. Most cars with oxygen sensors in good health will have all 3 long term trims in the range -5% to +5%, but -10% to +10% is generally considered acceptable.

Other issues that I'm aware of that can show up in the long term trims:
- injector clogging (similar effect to oxygen sensor failure, though not usually as extreme);
- vacuum leaks in the intake tract (low LTFT is significantly more positive than med & high).

The logs I have are from over 2 years ago but they seem to be in the 3-5% range. Will have to do some more soon to compare. Thanks for the info WytWun.

With Evoscan, the items to watch to detect oxygen sensor issues are the long term fuel trims (LTFTs). Once they go more extreme than +/- 10% there's an issue that needs sorting.

The long term fuel trims are rolling averages of the difference between the amount of fuel the ECU is programmed to expect is required and the amount of fuel that is actually required based on the oxygen sensor feedback - positive trims indicate more fuel required and negative trims indicated less fuel required.

There are 3 trims loggable:
- low (aka idle trim; applies to low engine speeds and loads)
- med (moderate engine speeds and loads)
- high (higher engine speeds and loads, usually freeway/highway running).

Oxygen sensors normally read lean as they fail, so the long term trims eventually reach the positive limit (+25% I believe) in this case. Most cars with oxygen sensors in good health will have all 3 long term trims in the range -5% to +5%, but -10% to +10% is generally considered acceptable.

Other issues that I'm aware of that can show up in the long term trims:
- injector clogging (similar effect to oxygen sensor failure, though not usually as extreme);
- vacuum leaks in the intake tract (low LTFT is significantly more positive than med & high).

Im having issues logging mine. They logged when I first got Evoscan. Started at 4% and got upto 15% through rev range, now just reading 0%

Hopefully mines just got a crook o2 sensor. Ordered one just awaiting delivery

I once asked the dealer about genuine spark plugs, they were $8ea and he said they were just NGK.

My 2002 fronts were NGK Rs, yes.

But today I discovered my factory-fit rear bank were Champions... Ugh!!

So does anybody know the manufacturer of the OEM sensor? Walker, Denso, NTK?

Original oxygen sensor in my TF was NTK/NGK. I just replaced it, after 360,000 ks, and will report back when I have a better idea of any fuel savings.

Is there any chance that you could post an image of the sensor, up close and including the connector?

Thanks.

Just my opinion here.

I used to be a smug b@stard and by oxygen sensors from the U.S. for cheap. Never thought it could be a problem.

Then I mate of mine had issues with one of the Denso oxygen sensors I used to think we're great.

While I don't think I've had an oxygen sensor issue buying them from the U.S. I have found my car runs far better than ever with a genuine oxygen sensor. I'm seeing 11.0/100km in a 3.8 AWD in traffic if I drive right.

So I'm sold. If ever I need a new oxygen sensor it's going to be a genuine one.

Genuine, for an AWD TJ, they're $240.

I can do genuine ones for $135

The oxy sensor is a little like a spark plug in the sense it has a life span. Yes after 200k it may still work but will be slow to react as it is in the exhaust stream.

Personally I think that when the platinum plugs are done the oxy sensor should be done also.

My 2002 fronts were NGK Rs, yes.

But today I discovered my factory-fit rear bank were Champions... Ugh!!

TJ, L and W had Champions in them for some reason, Mits must have made some sort of deal

NGK are the factory branded as NTK

TJ, L and W had Champions in them for some reason, Mits must have made some sort of deal

Done a deal with the yank devil, if he asketh me. Extracted & banished to the junk box together with some sets of RN9YCCs that wouldn't play nice on my AstronII.

KJ seems to have revived a few extra ponies up top, now feels as peppy as TH that I still remember fondly for its snappier response.

Done a deal with the yank devil, if he asketh me. Extracted & banished to the junk box together with some sets of RN9YCCs that wouldn't play nice on my AstronII.

KJ seems to have revived a few extra ponies up top, now feels as peppy as TH that I still remember fondly for its snappier response.

Same here, changed my rear plugs with some new NGK Platinums, seems to go better now . The plugs in there were NGK but were nearly 110, 000km old. Recently done the timing belt as well which was either stretched or out a tooth, now it performs like a V6 should with plently of low down grunt like I remember when I first got it.

thinking of doing the O2 sensor too... haha, ONCE MY BACK RECOVERS from 2d of leaning over enginebay :(

better running might not just be the new plugs all round, i also took the time to flush out the MAF, TB & idle servo. Also took a lot more time making sure every gasket & pipework interface wouldn't leak air, flushed out sockets with electric contact cleaner etc

didn't have the patience to swap plug leads, that can wait till the cover seals really need doing :)

thinking of doing the O2 sensor too... haha, ONCE MY BACK RECOVERS from 2d of leaning over enginebay :(



Hah!
Try undoing the three bolts that hold in the aircon fan while lying on your back half in, half out of the car in 36 degree heat!

No sympathy for you, Sir! lol

thinking of doing the O2 sensor too... haha, ONCE MY BACK RECOVERS from 2d of leaning over enginebay :(

better running might not just be the new plugs all round, i also took the time to flush out the MAF, TB & idle servo. Also took a lot more time making sure every gasket & pipework interface wouldn't leak air, flushed out sockets with electric contact cleaner etc

didn't have the patience to swap plug leads, that can wait till the cover seals really need doing :)

I also cleaned the TB & idle air valve when changing the plugs as it was already apart. Also noticed a small section of the coating on the metal gasket was loose so I used some loctite teflon paste to seal it up as I had no spare gasket. Will have to get one for next time it comes apart.

Hah!
Try undoing the three bolts that hold in the aircon fan while lying on your back half in, half out of the car in 36 degree heat!

No sympathy for you, Sir! lol

You jinx minx!!

That's been on my to-do list for few years, wanting to yank out the fan to clean it out :( think some shrapnel has fallen inside.

So u start by taking off the glovebox...? :D thanks for tip, might takeout the shotgun seat first for more working room.

Also noticed a small section of the coating on the metal gasket was loose so I used some loctite teflon paste to seal it up as I had no spare gasket. Will have to get one for next time it comes apart.

yeah the runners' gasket seems to be some kind of powder coating haha. Mine (virgin fitted from factory) lost a few chips at the edges but not at the perimeter traced by the mating surfaces... so I don't bother chasing a spare.

ran a thin bead of blue hylomar both sides. Didn't want to use anything that would set hard (like copper RTV) or anything that could be washed away by fuel (like grease or gasket goo).

Hylomar'd the TB and the crankcase vent gaskets too. :)