I have an 03 bonneville ssei and while troubleshooting a p0300 misfire code, I disconnected the crank position sensor to inspect the connection. I didn't remove the sensor I only disconnected it. When I plugged it back in and started the engine the misfire and p0300 code went away. Now, it'* throwing a p0303 code. The engine seems to run fine. Plenty of power and no hesitation. My question is......do I need to have the crank sensor re-learned at the dealer for only disconnecting it?? It never threw a p0303 code before I did this.

P0303 is cylinder #3 misfire. Are you sure you got the right code?

Yes that is correct. I got a p0303 cylinder 3 misfire.

Yes that is correct. I got a p0303 cylinder 3 misfire.

Swap plug wires 3 and 5 and see if the misfire follows. If it doesn't, swap plugs 3 and 5. If the misfire still doesn't move, then swap the coil pack for a one of the others. Last resort is to swap injectors, but that'* rare that a misfire is caused by an injector.

Swapped the wires no change. Plugs are brand new but I'll try it anyway. I swapped fuel injector 3 and 5 and am still waiting for the code again. I'll let you know. So this has nothing to do with the crank sensor being disconnected?

It shouldn't.