Mr. Dalton, I have read a lot of you on this site already, so I'm a little intimidated to ask you, "are you sure?"

I have a 1995 e320 Sedan. My understanding is that it is a 124, and the codes I used are from another Thread, saying #2 is the Heated Oxygen Sensor, #4 Air Injection System faulty hot film mass air flow sensor with hot wire, and #26 Upshift Delay Faulty.

This was read off a 16-code box (indicates 124?) with the reset and little light, by pins 2 and 4 (if I recall correctly) right by my battery, as you told me in an earlier response. I cycled this 3 times to be sure my reading was correct, and each time it was 2, 4, then 26.

So, when I look up the part on-line and calling parts stores, both indicate that there is an upstream and downstream sensor? Some even said, front and back.

I am a genius when it comes to computers, but a complete moron when it comes to this stuff, I think I know how you feel, so I appreciate your patience with me.