Terry, I tried to call but you have chosen not to return my call. I am sorry you did not understand our diagnostic check. I am sure you must not have understood because it was not what you told us was wrong. Actually it was something entirely different. You thought your oxygen sensors needed to be replaced. We found a rusted hole in your brake booster causing a massive vacuum leak that in turn caused a lean code for the oxygen sensors to be set. I assure you you would have been much more upset had we followed your diagnosis and after spending hundreds, if not thousands, it did not fix the problem, which it would not have. We did confirm your diagnosis of broken exhaust manifold bolts and leaking manifold gaskets. If you would like to talk further I am always available.