A warning: as with all things DME related, you can brick your car. I wanted to learn this and decided to risk it. But my first attempt triggered the immobilizer (more on that later). But proceed at your own risk, I am not an expert just offering a simple write-up of my experience.
Last year I had to replace my engine since my head cracked between 4&5 cylinders. While doing that I went ahead and installed BB catless headers and deleted my SAP. I ended up using Renovelo to code off post-catalytic converter O2 sensors and SAP, and really enjoyed the product.
I was new to DME programming, but decided to go this route instead of Active Autowerks flash. I wasn't sure if AA removed sap, and I have a friend who does Dyno tuning. Eventually I plan to get a full tune, but this is just a quick write-up of how to delete secondary O2 sensors and SAP.
Renovelo was simple enough to use and is a pretty clean gui. DME programming is a little overwhelming at first, but was a fairly simple process once I found the parameter names and what to change them to. I found https://www.ms4x.net/index.php?title=Siemens_MS45 to be extremely helpful in this. They have parameters listed and what they do for each. At the bottom of the page is the list of parameters that change SAP and O2 settings as well as top speed and idle.
To flash your DME you first have to download the full binary file from the car. This takes about 45 minutes and most people recommend to use a trickle charger while downloading and uploading since if it doesn't finish or uploads half the file it can brick the DME. Also I'm pretty sure you can use the PA soft cables with Renovelo, but I went ahead and grabbed theirs since it needed a certain pin jumped.
Step 1- Install software and drivers. Renovelo has a very good install write-up just follow his instructions.
Step 2- Open the software and request license activation and DME license activation. Make sure to check your spam, Jeff's emails made it into my junk folder.
Step 3- Attach trickle charger, insert OBDii reader, and turn key to on position but do not start the car. Turn off air and other accessories to save the battery from draining. Then select download full binary at the top left. This takes 45 minutes to an hour.
Step 4- Save the file as your OEM DME. I saved 5 copies in different locations. This is the what you want to flash back to if you have issues with your upload.
Step 5- Select file open, and open your downloaded binary. FIRST SAVE UBDER A DIFFERENT NAME TO MAKE SURE YOU DONT OVERWRITE YOUR OEM DME FILE.
Opening this .bin file will open a list of the parameters for your DME whether its ms43, ms45.1, etc in the left window. These are the parameters and values that control all aspects of your engine. This is where MS4x.net wikis come in handy.
Step 6- Select the parameters you'd like to change, and set them to the correct values. Below is a picture of the parameters I opened to delete SAP and Post O2. I ended up not changing the top right map so ignore that window.
Step 7- When you are happy with your changes select file save. ONCE AGAIN MAKE SURE YOU ARE NOT SAVONG OVER THE ORIGINAL DME DOWNLOAD.
STEP 8- Make sure trickle charger is attached and turned on. Attach OBDii cord and turn key to on position but DO NOT start. Then press the little arrow below upload and select upload full binary. This should take 20-45 minutes. Do not touch or change anything on the car in the mean time.
Step 9-
Step 10- Press the clear adaptations button, and clear any check engine codes if you haven't already.
Step 10- TURN KEY TO OFF POSITION FIRST. Then you should be good to start the car, and see if you didn't ruin it.
I forgot to switch my key off during my first flash and it triggered the immobilizer. I had to find an INPA copy to re-sync the DME and EWS. My second flash went flawlessly.
I still have to reinstall my PA soft to double check that O2 sensors and SAP shows up on scans as not available. If that is the case it would pass emissions inspections but not sniffer tests (unless performance cats where added).
I hope this helps anyone considering it, but once again I am by no means an expert on the subject and your mileage may vary. Do this at your own risk.