hey scotty! so i have been having problems with my 99 chrysler town n country. It runs fine for a while and when it warms up and runs a few miles it starts to sputter like its running out of gas and then doesnt want to go anywhere when you stop. sometimes eventually stalling altogether. I had codes p0171 and p0174. p0174 went away and p0171 stayed. I have replaced the cataylic converter and muffler and a couple of o2 sensors but the problem is still there. I have checked for leaks and cant find anything, PLEASE HELP ME SCOTTY!!!!!! THANKS

a wek fuel pump can do that, as can a bad maf sensor or serious vacuum leaks. Pressure test the fuel pump FIRST