well after 950.00 my sons 94 got new stock rear rotors,bled brakes, valve body from scp installed, replaced front caliper bolts and attemp at correcting a 15mph off speedo which is now about 7.. i know price a bit.. excessive... the 3 most important issues to be repaired were not resolved....= vacuum guage not reading 19-20 at idle closer to 10-11/ and firm ride light not illuminating/...slight hesitation at light throttle not at wot or idle..... any one want to take some stabs at what to look at ? only codes are related to the dpfe being most likely bad,, before you say vacuum leak i figure if vernon of all people, says theres no vacuum leak there cant be one..i had done all the correct sealing one should do before vernon got it. note to self do all repairs to your s/c yourself , youll save alot of money and learn some stuff along the way.... i knew this lesson 12 years and 5 supercoupes later but my son and his first s/c had to figure it out sooner or later so thats out of the way...... questions here are where to start diagnosing firm ride issue and can faulty dpfe or egr cause part throttle hesitating not severe but aggravating... thanks guys...