i jus put in my new tranny and new clutch in my ef9 and it keeps throwing a code 43 when i drive it for bout 5-10 minutes. car runs like a champ but keeps throwing code 43. vacuum lines are good, FPR seems ok, haven't checked fuel pressure or o2 sensor. but before the new tranny and clutch went in it was running fine wit no check engine light coming on. can somebody please shed some light for me???

 

Code 43 is Fuel Supply System. Check the fuel pressure, fuel pressure regulator. Check the o2 sensor and also check vacuum leaks? What is your fuel pressure when turn the key to accessory position, you should hear the fuel pump operate like a hissing sound. Do you have AEM fuel rail with a fuel pressure display tach by fpr. If below 37 bad fuel pump. either clogged or fuel is been restricted to the fuel injectors.