Codes P0122, P0452 and P0107

[dlong]

I have a 2003 Protege ES with codes P0122, Throttle Position Sensor circuit low, P0452 evaporative pressure sensor low, and P0107 MAP sensor circuit low. While driving the car will intermittently surge or buck. I replaced the Throttle Position Sensor, and MAP Sensor. Car still bucked while driving so took it to a local auto repair shop. Local repair shop confirmed the stored codes, cleared the codes, and confirmed all effected sensors were reading normal. They drove the car and could not duplicate the bucking or lurching. Several hours after leaving the repair shop the check engine light went back on and the bucking returned.

Any thoughts? I found one thread that indicated the problem may be related to a faulty EGR Boost Sensor, but I didn't think the 2003's even have an EGR boost sensor. Plugged vacuum hose somewhere?? Loose ground?? I'm stumped. Before I bring it into the shop again I thought I would throw the problem out here.

Any help would be appreciated.

[goldstar]

Yes, the 2003s (as with all FS-DE engines) have an EGR boost sensor, an EGR boost sensor solenoid valve and an EGR valve.