mass airflow sensor
 

does anyone recomend buying a suposedly slightly used granatelli MAS for $75? What kind of lifespan do these have? thanks.

I have never heard anybody actually say that they were happy with a Granitelli unit. I have heard a lot of people say that they have had prblems with them though.

I have one on my 98, and it works well. I dropped almost 2 tenths in the quarter, and have had it for a year with no problems. It is quite expensive new, but I figured that I might need it when I put a new throttle body on. New 80mm throttle body will be installed this coming weekend, which is much later than I hoped.

Hmm, maybe this is a case of only hearing about the bad side of something.

What is the Mass Airflow system? Where does it go and what does it do?

Should be referred to as MAFS (Mass Air Flow Sensor). Integral part of the EFI system in 96 + Vortec engines.
EFI uses either a MAFS or MAPS (Manifold absolute pressure sensor) to determine air intake.
The MAFS is much more adaptable and reads true airflow, while the MAPS can only guess airflow based on a set table in the ECM that corresponds to pressure in the manifold.
Vortec engines use Mass Air Flow with a MAP back-up system.

Thanks for the info. One more thing to look at.