About a month ago my 89 ford ranger (with a 93 engine 2.3l) started surging but only when accelerating. sorta seemed like it was either out of gas or was fire correctly .. my father is a helicopter mechanic and has some experince with automotive and we both thought that it was a faulty fuel pump as ive been told that that year ranger had fault ones that tended to go out .. after replacig the pump assembly which was in the tank the problem continued. any how i replaced the sparkplugs and wires just as a normall tune up . the problem of course contiued. so i bought a code scanner and got code indicating the coolant temp sensor voltage was out of range, the egr valve position sensor indicating that it either was not opening correctly or not seated correctly and the o2 sensor was always reading the fuel to be lean and not switching ... i cant figure this problem out ive read alot of forums some saying that the cat might be the problem but recently the truck dies on me but always restarts.. some onehelp me .