I have a 98 2.7L with 230000 miles, automatic. A few months ago, it started stalling when I came to a stop or let off the throttle traveling at speeds <25. In addition, when I am driving on the freeway and take my foot off the gas pedal, the truck sometimes downshifts out of O/D briefly. I have since inspected the vacuum lines, cleaned the air filter, replaced the fuel filter, replaced the IAC valve, replaced the exhaust manifold gasket (it was shot, leaking exhaust into the engine compartment), and about every standard troubleshooting procedure I know of. After all of this, the engine stalls far less frequently, runs smoother, and is a tad faster, nonetheless, it still stalls.
I am thinking at this point I am dealing with a throttle position sensor or a torque converter/transmission valve/solenoid issue.
The truck is not throwing any CELs and otherwise drives great.
Does anyone out there have experience with such issues?