This is 1994 RAnger with manual transmisson and 4.0L First, my exhaust gets loud enough to annoy me when engine is warm. Probably wouldnt get me a ticket unless I really stomped on pedal in front of a cop. Its quiet at idle but any acceleration and it sounds like a bad muffler. Quiets when at speed. Doesnt do this when cold. I replaced the muffler and it helped a little bit, but still lot noisier than I like. Used piece heater hose as stethescope and noise is out tailpipe, not from any joint/connection. Second I am now getting check engine light. Its OBD1 and only get code 70, ECM failure??? Thing runs fine, idles fine, enough power. Trying to see what the heck it means, google keeps bringing up something about bad data connection with dash??? Gauges all work, so???