00civicman

i recently put in a d15b in my 2000 civic and did a 5 speed conversion the motor is obd1 i put in a brand new dizzy, odb1 conversion, and p28 ecu i havent really been driving the car but when i do it idles to low or to high sometimes and a code is bein thrown the car sometimes cuts off in neutral and when driving the car kinda jerks when in 3rd and foot is off gas and the car sounds like it has flat tires when driven but the tires are fine and full of air i was thinking axles need to be replaced because i kept the auto tranny axles and i was also thinking i might need the ecu tuned just l just want to hear some opinions on what the problem could be