I replaced the MAF because is was getting trouble code 12. Now I am getting trouble codes 11 Crank Angle Sensor, 12 Mass Air Flow Sensor, 21 Ignition Signal Circuit, 51 Injector Analysis but the car seems to be running fine. Any Ideas about what is going on.

Also the check engine light is erratic. It is off at idle. It flashes when I first press the accelerator an remains off. It flashes again when the tach reaches idle speed then goes off.

Wow that's a lot of codes! Does putting your old MAF back in get you back to one code? Was your replacement MAF OEM new or used?

I would certainly check the electrical connections to your CAS and MAF. The injector analysis code could be a side effect of the engine not running properly. Also check for any hoses that might have been removed and not reconnected, especially the ones that connect to the main air duct between the MAF and throttle body, when you took the MAF off.

Heath