POSSESSEDZ

I have a 96 z28. The car hesitates and stumbles until it hits around 2500 rpm.
i took it to autozone and the codes i am getting are,
P0420
P1371
P1441

Any help to fix this will be appreciated.

thanks, Dave.

Injuneer

P0420 = Bank 1 catalytic conveter low oxygen storage.

Assuming you still have cats, either the driver's side cat is dead, or the O2 sensor is faulty. Swap the two after-cat O2 sensors side-to-side. If the problem stays on Bank 1, its a faulty cat (or possibly harness wire). If the problem follows the sensor to Bank 2 (P0430), its a sensor problem.

P1371 = Distributor ignition system - low resolution pulse loss.

This means the PCM can not find the signal from the Opti optical sensor that tells the PCM the cam position. It needs this to time the ignition and fire the injectors. If it can't find the low res pulse, it shuts down the fuel system. If your engine is still running, even poorly, this is a "stored" code, because if its an "active" code the engine wouldn't be running at all. Check the two harness connectors on the Opti harness for corrosion or pin damage. Clear the code and see how long it takes to come back. If you are having problems with the low res pulse, you may also be having problems with the high resolution pulse, which the PCM uses to "fine tune" the ignition timing. This one may not set a code until the high res pulse is completely gone, not just erratic.

P1441 = EVAP vacuum switch circuit high during non-purge

This indicates the EVAP purge solenoid is stuck open, possilby due to carbon particles. This code will also set if you have the two hoses on the EVAP purge solenoid swapped in the wrong positions. Could also be a faulty vacuum detection switch.