Oxygen Sensor

[GeoffSmith]

Ivar,

That would appear to be perfectly normal.

Geoff

[ivar]

Thank you, i appreciate youre quick response.

[GeoffSmith]

Hi guys (and girls) !
Does anybody know the correct reading from the o2 sensor ? On Elanscan the value jumps up and down between 0,1 and 3,6 V. (on idle). Is this correct, or a faulty sensor? Thanks for any answer.

There is a technical bit here. The ECU obviously amplifies the O2 output which is why it is reported as 0-~4V.

[Ellie]

In the interests of enlightening the uninformed, can anyone indicate where the O2 sensor is actually located on an S2?

[Enright]

It pokes through the hole in the Turbo heat shield.

[Ellie]

#161 thanks you!
There's some easy to digest technical info here : http://www.repcoservice.com/go/objectid ... 5B21FD70FB
& http://www.ausauto.com/index.php?page=d ... ry_id=1698

Also see (includes info on kit & aftermarket air/fuel mixture monitors & gauges): http://www.autospeed.com.au/cms/A_3032/article.html

Generic & OEM (USA site): http://www.automedicsupply.com/index.ph ... height=800
Denso: http://www.densoaftermarket.com/products/?id=1

see also: http://www.racepages.com/products/?N=16 ... 1+9166+773

[Ellie]

I have obtained from Auto Medic Supply (OxygenSensors.com) - the following url should take you direct to the Isuzu Impulse RS 1991 1.6L (1598cc) VIN code 4
www.automedicsupply.com/catalog.php?PHPSESSID=fdeead6c754510c01354570df18f739b&pkey=1176173

the Walker sensor... (pic below) and I can confirm that whilst the sensor is phsically smaller than the Denso equivalent, it is a direct replacement with a 22mm hex body (for spanner or sensor socket) and it does have the correct plug and mounting for the Elan S2.

The Walker package has the following:
Walker Oxygen Sensor Part No. 250-23127 (Isuzu (4) 1990-92 3-wire terminated)

"Oxygen sensors, if installed, are NON-returnable. Be sure to compare this sensor to the old one BEFORE installation."

Package contents - sensor with 3-wire connector, small tube of antiseize compound (copper coloured), instruction sheet.

Inner bag stamped with: 250-23127 IMO35 000 04C4

"Terminated Oxygen Sensor Instructions
1) apply 'high temp' antisieze to the oxygen sensor threads if not already coated.
2) install oxygen sensor into exhaust manifold and torque to 35 Ft Lbs.
3) on flanged applications install flange to exhaust manifold first, then mount sensor in flange. Note: a copper gasket is bonded to the flange and no additional gasket is required." [3 would not apply to Elan]

I cannot vouch for the performance of the Walker sensor compared to any other brand as I have just fitted it and have no data yet. I can say that the vehicle immediately performs better than before and appears to be as it should.

*Edit/addition: I have run the car (quite vigorously) a few times over several miles on different occasions. Judging by the wheelspins and objects getting rapidly smaller in the mirrors, all is indeed, quite well in the power delivery department! I have removed and inspected the sensor and the metal shroud (which lies inside the turbo manifold) is quite pristine and shiny. There is a hint of soot, which I assume has come from the initial startup and the ECU coming to terms with the new sensor voltages and subsequent fuel/air mix adjustment.

[Ellie]

Elanscan graph for O2 sensor output should look something like this...
(this graph using the Walker sensor (above) on a vigorous run from cold startup).

[GeoffSmith]

That's a good healthy signal you've got there.

[Ellie]

Oooooh Yeah! No more code 44 for me. Thanks to a bit of Kitty Fiddling and the LEC Forum, #161 is fit, healthy and frying tyres.

As the graph shows, the 1st 200 seconds or so are warm-up from cold whilst driving, then a spot of catch-me-if-you-can whilst the skies were blue and the temperature superb.

My advice is take regular Elanscan datasets to watch for any O2 sensor deterioration, then (using your pre-purchased & already-stored O2 sensor) replace the tired sensor when necessary. Don't forget the dab of antisieze to help with easy removal.

[GeoffSmith]

Careful with the antiseize though, as you can contaminate the sensor! The threads of the four wire one I picked up to play with were already loaded with antiseize.

[Ellie]

Absolutely! This was discussed in Nitroman's O2 Thread Chaser thread see Antisieze on sensor threads and I used just a dab applied to the turbo manifold threads only, by way of an old toothbrush. Don't want that pesky O2 sensor shearing off in the manifold when you remove it - that'll really spoil your day/week/month.

Yours came out OK Geoff?

[GeoffSmith]

NO! A complete pig which only came out by standing on a pipe wrench when I got the manifold off.

It's gone back in and the output is probably marginally OK but I want to change it before it takes root again.