1997 Boxster - OBD2 - How Many Lambda Probes??

[jcorallo]

Hi,

I only seems to have 2 Lambda probes on my 1997 Boxster - one on both sides of the car before each of the cats.

The parts manuals all say there should be one before and one after on each cat so four in total.

Am I being thick - I cannot see the third and fourth probes - are they hard to find?

Cheers,

Jules

 

[Richard_Hamilton]

Stop looking - I think you have found all there are. Early RoW Boxsters and 996's only had sensors before the cats. It was the US spec cars had them after the cats as well.

 

[Tool Pants]

I have a 1997. On a North America car we have 4. I think you have just 2, but then I have not been under a UK car

 

[jcorallo]

Ok- thanks - thats good - I'm not blind then!

I've lucky enough to have my own OBD2 lead/software for my laptop and was looking at the voltages coming off both sensors.

One sensor fluctuates, the other harldly moves. The below graphs were logged with the engine at idle:

So I guess I need a new sensor. Thank goodness there's only 2 of them - but if anyone wants to chime in and give an opinion on the above, any help much appreciated!

Jules

 

[Richard_Hamilton]

The DME Set Points in the manual show the voltage for the O2 sensor before the cat as 0.07-0.79, so it looks like the sensor relating to the top diagram is on the way out.

Edit: What interface and software are you using? Strictly speaking, I don't think RoW DME 5.2.2 is OBDII compliant. I have a mOByDic interface and Digimoto Lite software which is OBDII (and CAN) compliant, and it won't read the DME on my car, but works fine on my brother's C4, which has DME 7.2.

 

[jcorallo]

Hi,

My other car is a Golf VR6 and to help with diagnostics, I bought HEX-COM from Ross Tech http://www.ross-tech.com/ which looks to be the same sort of thing as the Durametric one on http://www.durametric.com/ - just hobbyist tools that do the job almost as well as the real things.

The HEX-COM has generic OBD2 capability so should work on any OBD2 compliant ECU - it reads my Boxsters ECU no problem what-so-ever. I cant read air bag / ABS / other modules though.

Cheers,

Jules