changed pluggs ,wires, po300 02,so tapped on rim of injecter lightly seem 2 do the trik now months later engine lite flashes car running good on upperspeed go to slow down stumbling starts codes r po300 01/02
po300 o1/o2 on 2003 Chevrolet Venture
Light flashing indicates a bad miss that could damage the catalytic converter. A coil may be failing after it gets hot or EGR sticking open after being at cruising speeds. Take it and get a tech to check the non continuous test data for specific cylinder misfires and for the EGR position sensor showing the valve is going shut when coming to a stop.
The easiest why to answer this is to give you some information regarding misfires. Fuel won't burn without air, air won't burn without fuel, if the combined mixture is not correct, then the explosion is not helpful. Obviously you want to save money and do things for yourself, with the knowledge you have learned. The tapping on the fuel injectors would say the connection might be a poor connection, or maybe a sticky injector. The slower speeds indicate a bad mixture ratio, either to much fuel, or to much air. Now all you want is an answer to fix your car, and I am advising you to check for the reason for the fault as we would have to do with the equipment we have to purchase to answer your questions and fix the problems. If any of this makes since to you, then your question has been answered, then you can find this or take it to someone who can.