My car has the 4.6 with a 2.3 Whipple, auto trans. It occasionally gives me a check engine light that tells me code 171 and 174. The codes say lean engine condition. I have to reset it once in a while. Now it randomly just turns it self off while going down the road. I replaced the fuel pump, fuel filter, and cleaned the MAF sensor. My mechanic has gone over everything 5 times but cant seem to find anything. Anyone have any ideas?