after repalcing whole clutch system, it now doesn't run right..have replaced the cat converter & fuel pump & regulator, map/maf, co2 sensors, cleand fuel injectors,new fuel filter air filter, tune up, still doesnt run right, no rough idle, seems fine until over 25mph then hesitates and given gas it surges, speedometer goes up & down over 55, the shop gave it back to me they cant find the problem it is using alot of gas,,please help..oh and NO it wont throw any codes ??? HELP !!!