some help here guys would be greatly appreciated! so i failed emissions again on my 1991 saab 900 turbo and its the same deal as two years ago when i failed. My NOx is too high. last year i took the test twice and failed and paid my mechanic two different bills. after the second fail, he took it personally to a test center (i have never heard of a mechanic doin this before) and it passsed, but i looked the papers fron to back: the cap on NOx is 1750 ppm and my car passed with 1747!!!!! i do not know what my mechanic did, and now two years later my car is failing with flying colors, that exhaust gas must be really hot. to my understanding nitrogen oxides are forming in my 4 combustion chambers because temp past ignition is too hot? and for this reason exhaust gas is too hot? any help would be greatly appreciated, i need to pass emissions on a budget! I love my car more than anything i have ever owned and want to take it with me back to college this year. what can or should i do?? thanks all for tips!