Mazda Repair: 2000 protege 1.6, maf sensor, vacuum leak

Question
at 2500rpms engine will cut out until it falls to 1500rpms then pick up to 2500 and drop again i have replaced tps,02 sensor and maf sensor and have not corrected problem.thanks for your time.

Answer
TPS seldom if ever fail

The symptoms point heavy to the MAS though you say you changed it.  Cross check for a vacuum leak or an air bleed at some connection.

Does it idle higher than normal?  If so check the ICS (idle control solenoid - ICS/IAV).  Engine off, key on the solenoid should click when unplugged/plugged.  Open the lines and throttle body cleaner it to death, let it soak, then blow it clear.  

Another common is the crank/cam position sensor, similar symptoms.  Do you have an MIL on?  (malfunction indicator lamp)  Not sure which that model uses.  Check the connections clean if needed, check the harness also.  You can wiggle the connectors while the engine is running to see if the harness or plug has an bad spot in it that affect the operation.