these are the codes that came up when i checked it last:

P0300, P07410, B2710, B1771, U1064

Ive been having some trouble with my deville when i start it and its cold it doesnt idle correctly it revs high and the drops and keeps revving up. ive replace the plugs with platinum 4s, the wires with bosch wires, the coil packs, and the ignition module. just last week i had it in the shop for the cam shaft sensor and they said it should have fixed it, but it didnt. cant anyone help me out and tell me whats going on. sometimes i come out to my car and the theft deterrant system is on and the computer says "STARTING DISABLED" someone help me. i would gladly appreciate it.

Most people report that the Northstar does not respond well to anything but A/C Delco plugs & wires.

Hunting or surging RPM sounds like a vacuum leak. Check the rubber coupler between the TB & manifold along with all other vacuum fittings. Also clean the TB.