How do I diagnose the O2 sensor?

[vi11ain]

I've fitted an O2 sensor and 1499 Everest chip to my 1990 SE. How can I check to see if the O2 sensor is working properly?

From looking at the Elanscan data, it displays either the CO Pot or the O2 sensor readings. How can I tell which is providing the information and how can I check to see whether it's correct?

Thanks

Ben

[rip]

If you've got a 1499 & your CEL is not on, your O2 sensor is working.

[GeoffSmith]

The closed loop manual (Figure EMJ4.9) says switching between 50mV and 950mV - I think there is a gain of x4 to the ElanScan readout so you should see the 'CO potentiometer/oxygen sensor?' line switching between ~0.2V and 4V but my old sensor was giving out ~0.5V to 3.5V and everything appeared alright. Also, I think that Flag 49 is the open loop flag (1=open loop) and Flag 51 is the closed loop flag (2=closed loop).

[aliensong]

I agree with GeoffSmith's opinion.

[DeeAitch]

Just checked mine as I thought the sensor might have given up on me - fuel consumption seems to be back where it was before I went closed loop.
Seems to switch from open loop Flag 49 to closed loop flag 51 after around 10 secs

MOT is due soon so I guess I'll find out then if it's working OK

[Monty]

Fitted Dico`s Elan with and O2 sensor and the correct chip but the engine light does not come on when the the O2 sensor is unplugged:?

[saska]

Fitted Dico`s Elan with and O2 sensor and the correct chip but the engine light does not come on when the the O2 sensor is unplugged:?

Which chip ? 1499 Everest /Kili /Std ?

[Monty]

Fitted Dico`s Elan with and O2 sensor and the correct chip but the engine light does not come on when the the O2 sensor is unplugged:?

Which chip ? 1499 Everest /Kili /Std ?

IIRC it was the 1499 stock chip

[DeeAitch]

Fitted Dico`s Elan with and O2 sensor and the correct chip but the engine light does not come on when the the O2 sensor is unplugged:?

When I fitted mine I seem to recall that ESM was of the opinion that it would not necessarily set a code if not working.
Might be worth dropping him a line to confirm.

[Monty]

Fitted Dico`s Elan with and O2 sensor and the correct chip but the engine light does not come on when the the O2 sensor is unplugged:?

When I fitted mine I seem to recall that ESM was of the opinion that it would not necessarily set a code if not working.
Might be worth dropping him a line to confirm.

I think Rippers did a ES on Dico`s Elan a while back and says the O2 sensor is working

Need to get in to using the ES myself as my Elan has hesitaion on hard acceleration

[rip]

I think Rippers did a ES on Dico`s Elan a while back and says the O2 sensor is working

I've just re-checked the scan I took from Dico's Elan & the O2 output appears to be bouncing around nicely between about 0.25v & 3.75v

Need to get in to using the ES myself as my Elan has hesitaion on hard acceleration

I'm surprised it has taken you this long.
All you need to get familiar is the program & some log files. I can mail you some log files if they will be of any use to you?

[Monty]

I'm surprised it has taken you this long.
All you need to get familiar is the program & some log files. I can mail you some log files if they will be of any use to you?

Did some ES years ago, the Elan doesn`t get out that much. I`ll do it one day but have to work out how to do the graphs etc. Maybe you could show me at Donny

[rip]

the Elan doesn`t get out that much.

Must be a Manchester thing

I`ll do it one day but have to work out how to do the graphs etc. Maybe you could show me at Donny

I'll be there.

[HJ2]

I've fitted an O2 sensor and 1499 Everest chip to my 1990 SE. How can I check to see if the O2 sensor is working properly?

Ben

You can use an oldfashioned scope to do this. If i recall right, you'll see a pulse train wich either gets compressed or stretched related to the O2 level.

[GeoffSmith]

Or use ES - see the Wiki for a picture of a correctly functioning sensor from cold:

[pjw12]

Fitted Dico`s Elan with and O2 sensor and the correct chip but the engine light does not come on when the the O2 sensor is unplugged:?

Which chip ? 1499 Everest /Kili /Std ?

IIRC it was the 1499 stock chip

Just fitted a sensor and chip to mine, all ok on start up, then 5 miles down the road CEL comes on. Despite having the wires present at the wheel arch block, ive got no connection between the sensor and ECU, so the same as it being disconnected really, the light doesn't automatically come on.

[saska]

Just fitted a sensor and chip to mine, all ok on start up, then 5 miles down the road CEL comes on. Despite having the wires present at the wheel arch block, ive got no connection between the sensor and ECU, so the same as it being disconnected really, the light doesn't automatically come on.

See Section 1 under Instructions HERE on how to fix this.

[pjw12]

Just fitted a sensor and chip to mine, all ok on start up, then 5 miles down the road CEL comes on. Despite having the wires present at the wheel arch block, ive got no connection between the sensor and ECU, so the same as it being disconnected really, the light doesn't automatically come on.

See Section 1 under Instructions HERE on how to fix this.

yeah, well on my way to doing that. Has any one else had to route new wires despite having a full RHFHC connector block?

[saska]

yeah, well on my way to doing that. Has any one else had to route new wires despite having a full RHFHC connector block?

Believe ashm did and then wrote it up in the Wiki a year or 2 back.

[pjw12]

'' Inspect the connector; pins 4 and 8 serve the O2 sensor. If there are wires connected to these pins on the main harness side then the necessary circuits are probably all in place''

ahh, hence the probably.... well mines one of the improbable ones built!