After two and a half years living in Mexico (quite nice, thanks for asking), our 2000 Toyota 4Runner with 170,000 miles is running a bit rough. We have had a hard time getting a computer diagnostic (check engine light comes and goes, almost always on last quarter tank of gas) because Toyota didn’t get established here until2004 and the dealers won’t work on a Toyota that is older than 2004. We replaced the fuel filter, but the vehicle has a tendancy to stall when accelerating from a stop. It seems to run smoothly once we are up to speed. The Pemex gas has a bad reputation for no detergents and possible water content. Do I need an injector cleaning? Could I have a sensor wearing out? Hard to diagnose without a computer analysis?