If your LT1 started running really rough. Missing badly especially at low RPM and you limped it home and got a code 33 "MAP Sensor". Would you order a new MAP sensor and try that first? I know what the FSM says but I do not have the means to test it the way the charts are laid out.

Anyone?

I would start by checking the vacumn connections as well as the electical hook up. You have to remove the MAP to inspect the vacumn connection which I think is on the bottom of the MAP.

Don't know what a new MAP would cost, but I suggest you consider gettin it diagnosed before replacing a part that may be good? Hope it's just a loose connection or something simple?

Lee, if you can check the voltage return (signal) and let me know what that is, assuming you have the 5v reference to it and vacuum.