1997 Toyota Camry Car surges at lower RPMs

I purchased my 97 Camry 1 year ago with 203,000 miles on it, and now have 216,000 miles. I had quite abit of work done at the time, including a tune-up. The car has surged while driving ever since I got it, but has become more noticible recently. I feel it most around 5 mph under light acceleration and also around 35-40 mph (right after auto tranny shifts into the next gear; i.E rpms drop). Under hard acceleration the car feels smooth. Occasionally the car won't idle (will stall). About 6 months ago the Check Engine Light would go on for 2-3 days, then go off. It seemed like the light would come on during high humidity days. This cycle repeated for a couple months, during which the following codes were pulled at the local auto parts store (P1410, P1411). I looked these up, and they seemed to point towards EGR Position Sensor. About 6 weeks ago the light came on, but didn't go off. I took it to the Toyota dealer, and they said there is a "misfire" problem (they didn't tell me the code number). They recommended replacing the ignition coils and spark plug wires. In reading your section "Car surges while driving", you mentioned that both sensors and coils (among other things) can cause surging. I was thinking of changing the EGR Position Sensor first (as it's the cheapest) and see what happens. Then change the coils/wire set. Do you think these could fix my surging problem? Also the local parts store has an "Airtex" brand sensor and coils. Is this a reliable brand?