96 LT1, code P0300 thrown.
 

I have a 96 LT1, that throw the P0300 code, which is Multiple Cylinder Misfire. I checked all the spark plug wires and various sensors and that checked out to be okay. I leaning toward a bad optispark as the car started stumbling and hesitating and harder to start. Does anyone here know if code P0300 leads towards a bad optispark on 96 vettes? Thanks in advance for any help. By the way the vette has over 70k miles.

I think it sounds like a module next to the coil in the front passenger side of the motor.

Thanks RED, I'm going to replace the cap & rotor first and see what that does.

It took new O2 sensors and one fule injector to cure the P0300 my LT4 issued a little over a year ago. The shop manuel has a long list of things to do to try and isolate what is causing the general misfire code. I ended up paying out the nose for GM to find and fix it.

Good Luck!.............MickyD

Thanks for the reply Micky.

I have the same problem. I replaced all my plugs/wires, new opti/water pump, new converters, and all new O2 sensors. I have the code 0300 and 0131 (bank 1 sensor 1 low voltage to o2 sensor) I am gong to get one new O2 sensor and hope that cures it, I also have a used set of injectors on the way.

Not sure about replaceing your opti cap and rotor. If you are going to go that far, I would replace the entire unit...you might want to try what MickeyD suggested first.

Darin

Yeah, I have relaced a o2 sensor about a year ago on this car, code # P0157, Circuit Low Voltage (Bank 2 Sensor 2) and that cured the problem but this time the car is getting harder to start and is stuttering and hesitating leading me to think its ignition related. I appreciate all the sugestions though as they might help me in the long run, thanks again guys.

That's the code my 96 LT1 threw both times I had to replace the opti. Leading up to the code was a general feeling the auto trans was slipping esp at <50% throttle. Both times I thought my trans was going out. Is your H2O pump losing fluid through the H2O pump's weep hole?

I just replaced the bad O2 sensor and it runs perfect now! No codes or hesitation...That's a relief, now onto another project!

The water pump doesn't seem to be leaking as it was one of the first things I checked. Tried to start the car yesterday wouldn't start up. I'm going to order the MSD cap and rotor to see what happens and move on from there. I'll let you guys know if it fixes it, thanks again.