Mazda mvp 03 spark plugs #5 and #6 are not firing. I pull the conector at idle and nothing. Ive cleaned and checked the injectors. New spark plugs. Ive checked fire, fuel and compression. All seems ok. The computer code says o2 sensor1 bank1. Will the bad o2 sensor cause this misfire in the cylinders?

you need to isolate which cylinder it is first may help.
while running use insulated pliers to pull each plug wire off plug or cap separately, you will hear idle change/drop when a good cylinder is pulled. it will not change when not firing cylinder is pulled. now u got the cylinder and can double check plug, wire connections there. see if that wire sparks on a ground or plug to check spark and eliminate that issue. if you get a zap you need a better insulated pliers, but you know that wire is good. Remember the 3 things needed on all engines- Spark, Fuel, Air. oh yes and Compression. if you have spark, then have cylinder compression tested 120-150psi is still good. 80psi sucks and you have bad rings or valves., fuel cleaner may help in that situation, rare fix, but cheaper than a new engine.

Try checking the injector, on my cars I swap it with one of the other ones and if its doing the same on other cylinder you know its stuffed so then clean it if still dosn,t work replace. seaya Neil

Code 306 means cylinder 6 is not producing power. And as you know it takes fuel, spark, and compression at the right time to make power.
Generally, if the injector is firing at the right time the spark plug should be firing as well.
Are you sure the plug is firing ? And is it possible injector 6 has no fuel to spray ?

Cam sensor. I have had the same problem, we have replaced air intake, crank shaft sensor, fuel injectors, coils, spark plugs, converters, and the cam sensor has seemed to help so far

Could be a bad spark plug or bad injector.
You could switch plugs with another cylinder to eliminate the plugs.
Same thing with the injectors.

REmove the idle control valve, clean and replace. Check plug wires, check fuel filter and fuel injectors.

What was the condition of the spark plug when replaced, was it indicating to a lean or a rich air fuel ratio. When is it misfiring?? during idle or while driving. The easy way to see if it's misfire during idle, disconnect the #2 wire from the plug and run the engine and see if there is any difference in the idle. If there is then the plug is firing and your getting the misfire during driving and that could be caused by a dirty fuel injector in cylinder #2 and may need it cleaned of replaced, but check the wire harness to the fuel injector it self be fore you go through all that. Good luck and keep me posted, be glad to help

It might be a fuel injector. Check injectors connectors they might be loose.

you may need to clean the injectors
what you can do is
you can buy some injector cleaner and see if this helps
make Shaw you get a decent brand as the cheep ones do not work as good
drive around with this in your gas tank
when you have in in your gas tank it helps clean them if you do some harsh acceleration but don't race the motor and don't speed
in other words get to the speed limit fast
this will apply pressure and will push through any gunk build up
there may be some smoke for a while from the exhaust but is will go back to normal when the fuel injector has finished cleaning and all the build up is gone
hopes this helps

123456 turning clockwise. kinda weird but thats what the book said.