Another one for the smart guys. Like the title says, does anyone know where lambda information is located on these cars? Obviously it's on the OBD port but how is it transmitted there?

The OBD2 standard provides for a number of things one can request from the DME.

Among these are short and long term fuel trims, intake manifold absolute pressure (if available), ignition timing advance, intake air temperature, air flow rate from mass air flow sensor, absolute throttle position, and #1 and #2 "lambda" (narrow band oxygen sensor) readings.

The 996 Turbo (at least my 2003 Turbo, uses ISO-9141-2 protocol and not CAN, at least for OBD2 communication) and I can use my faithful Actron code reader/data viewer/logger to view most of the above except the #1 sensors. (I also have access to a plug in self-contained data logger which I can configure to query up to 4 data items besides speed and log these every 5 seconds, except speed which can be logged every second.)

The Turbo uses wide band sensors in the #1 sensor location and wide band sensors are not supported in the lower 32 PIDs (parameter IDs).

To get those you need to query for PID 34 (Bank 1, sensor 1) and 36 (Bank 2, sensor 1).

Most standard OBD2 code readers/data viewers do not support these higher PIDs so you'll need a "Porsche" specific data logger in order to obtain these.

John - I'm doing this right now (literally putting the IDe in the motec). I'm testing this weekend and will send to you if you want. Aiming to get lambda and short and long term trims of the obd. They aren't on the CAN. Challenge with the obd is you have to request to get a response. Will see what type of rate I can get.

Ain't that $34 and $38 hex?

Great. Please let me know. I spoke with Phil at Motec today. He is one of their support engineers and told me you would need it over CAN hi or CAN low in order for Motec to read it. All the 997 and later cars have it. I'm trying to figure out if there is a way to get it over CAN in the 996 platform otherwise I will have to install a second set of wideband O2 sensors in conduction with the Motec Lambda to CAN module.

There are a number of different PIDs to use depending upon which sensor and which bank. I just skimmed over the chart that listed the PID and sensor number/location and I might have gotten the numbers wrong.

If you need the details just ask and I'll type in the PID numbers and which sensors are associated with each PID.

installing a motec? if so which one?

I've had Motec on the car for 2 years now. Great set up. After speaking with Motec we've decided to add the extra set of Motec/Bosch LSU 4.9 wideband sensors which will integrate with the existing C185 dash logger via the Motec LTCD (lambda to CAN dual) module. The reason that Motec does this is to get the highest update rate possible that they can not get from the signal that is available on the 996. The Bosch 4.9 wideband sensors are also a newer generation than the OEM Bosch widebands on the car. This will allow us to continually log an monitor Lambdas on both banks and have alarms set up in case lambdas go lean for any reason. We are already doing this with fuel pressure so this would be just another layer of protection. Plus, if we decide to go with a Motec ECU down the road at some point then the lambda sensors will already be in place.

nice - I have been using the new LSU 4.9 sensors for a few years and they work good.

The OEM Bosch sensors are LSU4 on the 996TT/GT2. Not sure on the 997

I use the faster 4.9 with the standalone not the OEM widebands.

10-4. Yep, those are the ones Motec uses.