TPS? Sure could be. It's just as likely it's a dozen or more other things too. You could empty a bank account throwing parts at it. Unfortunately, at this point you have very little to go on. What to do?
First, I would change gas stations and run a few tanks through it. You may have gotten some bad gas. Second, try the free things first. Check sensor, plug wire and battery connections for security and corrosion. A trouble spot on 4th generation vans is the IPM (fuse box). It's got a corrosion problem. If there's corrosion on the relay connections, in particular the ASD and fuel pump relays, it's a pretty good bet there's more problems inside. Another spot is the wire harness running near the exhaust manifold on the back of the engine. I'm reading way too many threads reporting the wire insulation melts exposing bare wire and shorting to ground. It mainly effects fuel injectors.
If this continues as a very intermittent problem consider having the dealer install what's called a co-pilot. It's a scanner that monitors many engine related functions as you drive. If the sputtering happens, the data collected would at least reveal a clue if not THE fix.
Last edited by Cougar41; 01-25-2012 at 06:08 PM.