Hello,
Previosly I went to Auto Zone to get an OBDII reading for my 97 C280. It was determined that I needed an air mass sensor or possibly an oxygen sensor. I went for the easiest fix first,which was the air mass sensor. I reset the engine light and everything was fine for a couple of weeks. Well, it's back on. I took it back to Auto Zone to get another reading and talk to someone. The manager is certain that I need an oxygen sensor. I believe I agree with him. While doing the reading,though, another code popped up. It was P0715. The manager said that means there is a problem with the input turbin speed sensor circuit. He went on to tell me that it was located inside the transmission. Has anyone out there experienced this? Is it something that I could do myself or will it be better to take it to a mechanic? Ijust don't want to get ripped off...again. Is it very expensive if I do take it in? I have tried to look up information on the speed sensor, but have found very little information. Any feedback would be appreciated.