I'm putting together a stock 5.0 engine and have added a mass-flo conversion kit, which is just the intake mass air and a chip for the computer. Before calling Chris I wanted to put this out to the forum faithful whom have already done so much to help me get my car to where it is. First is it neccesary to use the chip? Second with the chip I have gotten it to run at about 75% of where it used to be but it runs real rough and tends to bog around 3000 rpm has anyone had this sistuation is it just normal massflo start up and learning or do I have a problem? Lastly for the 91 5.0 ford had two firing orders one for the h.o. and one regular if somehow the chip that I have was for the non h.o. firing order would the car even run or would it act as thought the plugs were all on back *sswards? Thank you all in advance oh and by the way when I put the car on a code scanner it gave me some codes about the idle being out of specified range how badly could this affect it?