I got the sensor from The Benz Bin
However, by the sounds of your problem, this might not cure it. But its not expensive ($60) so its worth a shot. Have some small thick O-Rings on hand, your most likely going to rip the old one getting it off. Please dont hesitate with any question. You might want to check your codes before you order anything. see if anything comes out. If you dont know how, let me know, I can walk you thru the process. Its quite simple. Just make sure you have an analog volt meter.