new Boxster owner- engine light on :(

[rodracer]

Hey guys.. new member here and a new owner of a 2000 boxster (black) with 35K miles.

I put about 500 miles on it and now the engine light is on, with that there seemed to be a lower power output at 3K RPM and up. The engine codes that came up were 1133 and 1127 which reads as Manufacturer Controlled fuel air ratio..

After research over the weekend it seems 3 things could be causing it..

1.ever-popular MAP sensor
2.Vacuum leak in the evap system
3. any combination of the (4) O2 sensors

my idea is to replace the MAP sensor first about 200 bucks.. then see what happens.. think thats the right start?

Thanks in advance for your help!