What is your question?
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What is your question?
I went to get a smog and it failed and it had four codes so I did tune up and changed spark plugs and wires and oil change and o2 sensors all four.. but I still have code 300 multiple miss fire and and code 420 low lean efficiency on bank 1.. what else could it be.. everyone giving me the run around.. please help me..
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P0300 is random misfire (not identifying a particular cylinder) P0301 would be misfire #1 cyl, P0302 would be misfire cyl #2 ect..... A misfire could be a vacuum leak at the intake manifold or intake ducting, a bad air flow meter, bad plugs, lean fuel trim (insufficient fuel pressure/delivery) excess EGR or many things unfortunately. P0420 is low catalytic converter efficiency which could be caused by a misfire having caused the cat. converter to fail Fix the misfire and keep your fingers crossed that the cat. converter will then clean up the emissions and not trigger a P0420 code.
so it could still be the catalytic converter.. even thou on the smog it says it passed... thank you for taking the time to help me.. how do I figure out what is causing the misfire...
I had it checked for leaks there are none.. whats my nest step...lol