motor is in and it doesnt run very good. I have a code. code 34(powertrain control module). what does this mean and what do i do to fix it because i have an LT4 hotcam and it sounds like i have a 306. i also got a tune from PCm forless for the cam.Im sure i have to adjust the rockers still, but why do i have this code? thanks.

 

DTC 34 = Manifold Absolute Pressure (MAP) sensor circuit (signal voltage low, high vacuum)

Check the connection to your MAP sensor.

 

i dont understand why it would throw a PCM code... is their not a MAP sensor code? The car also bucks horribly until i clear 2000 Rpms, and when it gets warm it runs a little better.. Is that because of the map sensor