Tranny? Fuel System? HELP! 95 3.3 160K

From what I've read, there are quite a few out there who have had this same problem, but there are quite a few things it could be so if anyone could be more specific, I'd sure appreciate it. I bought my 95 3.3 minivan about a year ago from the original owner. I believe it had regular maintenance, but has the original transmission. It ran great up until now. I recently moved to about 1200 feet above sea level. When traveling uphill over a mountain pass, it will start to surge and sputter as though I'm running out of gas. The RPM's will usually drop from aprox. 4000 down to 2000, surging in between. Accelaration doesn't help. I have to pump the gas pedal to get it to sputter up to the summit. It seems to be getting worse. My husband has recently employed the "FLOOR IT" technique. He opens it up until it sputters into a flat out beat-run. Usually the problem eases off upon descent. I'm hoping it's a fuel sytem problem (cheaper!) but I'm concerned because the transmission has recently started acting up in cold weather. It won't catch into drive immediately after reversing, and some times slips going out our driveway (uphill, dirt road.) Engine fault codes are 32/EGR solenoid circuit or EGR system failure (the car is from California) and 21/Oxygen sensor signal. My cousin is a Mopar-head so he can do the work, but he's not great at diagnostics. Anybody have any recommendations?

Change the EGR and the O2 sensor. Be sure to clean out the EGR hole (behind the sensor) and don't use any sealer on the EGR Valve (will leech into the EGR hole!)

Your codes may then start showing you a Throttle position sensor bad. This is a likely cause of your main problem, although a clogged catalytic converter, or failing fuel pump can also give this symptom.

Hope that helps,

Slantsixness