I had a muffler place install my dp recently. They used a torch to loosen the bolts by the o2 housing and must have torch the o2 sensor as well because it's not reading properly anymore. The sensor thinks im running very lean! I read somewhere that the coumputer shut off the A/C went your rev's get high to protect the engine or a/c. Could the o2 sensor be at fault why my a/c is not blowing cool air. The blower works but no cool air comes out. I don't hear the compressor also.