what are the effects of not having a MAF sensor not calibrated right? say stock sensor in gt w/24lb injectors. is there a way to calibrate them yourself/mechanic or is only option to buy a new one?
The ecu expects to receive a signal from the maf that relates the mass of air moving across the sensor to a particular voltage. The signal sent by the maf has to match what the ecu is expecting or the ecu can't calculate the correct amount of fuel to inject. The ecu makes those calculations based on the injector size programmed in for that ecu. In the case of a stock HO ecu it expects 19 lb/hr injectors to be in place. In the case of the Cobra ecu it expects 24 lb/hr injectors to be in place. If you put 24 lb/hr units in with an ecu that's expecting 19 lb/hr units to be there you're gonna have lots of problems -- it's gonna run real rich.
To run 24's with an HO ecu you either need 1) an maf (C&L, Pro M, etc.) that's been set up for the 24 lb/hr injectors, or 2) you need to use a chip/Tweecer/PMS/etc. to tell the computer that you're running a different size injector than the 19's it's programmed for. There's not a simple 'adjustment' that you/your mechanic can do to account for the change in injector size.