1995 Dodge Ram 1500HD 2wd 5spd 175k.
After years of reliable service I recently noticed that I have no power when towing and can no longer accelerate to highway speeds as before. When I accelerate, the engine revs up to a point with full power then valve chatter but if I keep pushig the accelerator, chatter stops but it feels like I'm goin thru mud. Its like this at the top end of RPMs in any gear. Smells very rich at idle. Found a loose spark plug wire and a vacuum leak in a line that feeds the EGR control and repiared them. Same as before. Replaced the air filter, plugs, wires, cap & rotor and PCV and added a qt. Of Lucas. Checked compression, 90+ all cylinders. No more chatter but still no power. Could the EGR valve, its vacuum controller or maybe Throttle position sensor be the problem? Any good tests? Thanks in advance.