I was having trouble with my X5, it kept stalling and the check engine light was on. I had two diffternt "mechanics" try to fix it, they both found codes for the oxygen sensors, replaced one sensor and reset the light. when it came back on two days later I brought it back. After the second repair and over $600 the light came on again, at this point I realized these so called mechanics had little or no clue what they were doing. one of my friends recommended uptown auto, so i took it in, they found the oxygen sensor codes were still present. While I waited Pat, the mechanic found that the sensors were not connected properly and some wiring was damaged because the prevoius mechanic did not route or secure it properly. He repaired the wiring, connected the sensors and we went for a test drive. It has been three months since and i have not had any problems. I was amazed that they could find the problem and have me back on the road in two hours.