I did that, I didn’t find a real definitive picture until I found one that showed the heat shield above the catalytic converter. I noticed there is a heat shield above the straight pipe that someone put on, so I feel confident that is where the converter should be. I will check with my exhaust shop to see what they can offer as far as a replacement converter that has a bung for the O2 sensor before the converter. I don’t know why people remove things from these cars, especially an O2 sensor, knowing that they won’t run right afterwards. You can get by with that on some cars, but not a Mercedes.