Hello all,

I've done plenty of digging and found allot of info to get me this far, now I'm a little stuck and would love some advice.

I have a 2007 R500 4 Matic. I recently had it looked at but the local mb dealer and they were kind enough to diagnose two issues and give me the part numbers to source elsewhere, and upon fixing they would clear the codes and give me rego clearance.

So I replaced the steering angle sensor: thanks to those who have paved the path before me, I appreciate your knowledge.

I also bought a brand new air compressor for the AIRMATIC because it was throwing the code for the pressure sensor failure. Note: car still levels and raises no dramas.

I cleaned the plug with electrical contact cleaner, still randomly throws codes and I haven't replaced the pump because.... Well it works?!

Also ADS system throws the code for the y52 sensor failure and keeps ads in sport. So I've cleaned those plugs, measured R's and found that they were a problem, the bottom one not contacting well and not giving a reading. Once cleaned and tested I plug in, start the car, attach an Icarsoft reader, two codes:
Y52 front right (one I've cleaned and measured with a multimeter, gives 12.5ish ohms on both plugs)
And sometimes the other (can't remember the numbers) air compressor pressure sensor (which works but I haven't changed with the new pump)

So I clear the codes, remains still running, sand I disconnect my reader, I can happily use the ADS and AIRMATIC. If I turn the car off and on again, back to the start, cannot change out of sport!

Am I looking in the spot to fix this? Should I just replace both parts? I have a new pump and I've just ordered new leads out of frustration, I'm just concerned that this won't fix the issue!!

Thoughts or advice would be wonderful, I love this car!!