Lambda O2 Sensors on 182

[Davyboy888]

The pre-cat Lambda sensor was recently replaced on my 182 and it's still posting a fault code. So a friend and I hooked a Solus up today and looked at the voltage being sent by each of the sensors using a live data run. We then unplugged each sensor to see effect. It would seem that the post cat sensor was having no effect on the live data signal. We then unplugged each and put a multimeter across them. The pre-cat was registering a current flow... the post cat didn't appear to be. Finally we plugged the pre-cat sensor cable into the post cat sensor and there was a voltage registration on live data. So I'm thinking that the post-cat O2 sensor is not working and needs to be replaced. My questions :

o Are the two sensors different ?

o The Bosch part number on the new pre-cat sensor is 710745577, is that correct ?

o The part number on the post-cat sensor is 7700107433 along with 258006046 and 5851941711 98210 SE 4,2 <037> I'm not sure if that's the original Renault one or not, either way, just want to check if that's the correct one for the post-cat.

Thanks in advance.

 

[Louis]

Sensors are only different in the cable length, but both fit in either position IIRC.
The post-cat sensor stays on a set voltage and does not fluctuate, only the pre-cat does. Sensors cheapest from OPIEOILS.

 

[Davyboy888]

Sensors are only different in the cable length, but both fit in either position IIRC.
The post-cat sensor stays on a set voltage and does not fluctuate, only the pre-cat does. Sensors cheapest from OPIEOILS.

That's good to know.

The post cat sensor was registering 410mV whether plugged in or out. I think that value is an ECU generated default ? When I plugged the post cat sensor cable into the pre-cat sensor, it registered 1.295V and stayed at that value. Does that make sense ?

 

[Davyboy888]

Sensors are only different in the cable length, but both fit in either position IIRC.
The post-cat sensor stays on a set voltage and does not fluctuate, only the pre-cat does. Sensors cheapest from OPIEOILS.

A few more questions Louis, I hope you can help with. I bought a new Renault post cat sensor and fitted it this evening. We hooked up the Solus again to look at live data. The post cat sensor sat at 410mV or so until the engine temp reached 91C and then started to fluctuate... it eventually seemed to semi-stablise around 700mV or so, which seems very high. It also seemed to mirroring the pre-cat voltage which I read somewhere previously isn't a good sign. The car's on 77K so I'd be surprised if the cat's failed that early... but what I noticed below here may be the reason ?

The car is also registering a pre-cat code error and the Solus won't clear it. I noticed that the voltage of the pre cat sensor at ignition position 1 [i.e. ignition on and engine not running] is 2.5v. That seems extremely high. Now I know that the sensors have heaters in them, but I wouldn't have thought it would have a potential drop of that level even when the heater was on. What do you think ? Could there be a short in the loom to that sensor I wonder ? Or a short in the heater of the sensor ?

Any help/advice would be brilliant. Cheers.

 

[botfch]

Solus is shite when it comes to these cars, try clearing the codes on a different system if you have access to one.

 

[Davyboy888]

Solus is shite when it comes to these cars, try clearing the codes on a different system if you have access to one.

It's all I've got access to unfortunately