2003 h2 with p300 code
 

I have A 2003 H2 Giveing me a P300 code It Has new plugs,wires,both nox senors and all O2 senors have been replaced and have had the coils tested they are fine. but still giveing the code So i toke it to the dealer they can't figer out way it is giving the code it only gives the code in the mid RPM range the dealer tested the computer said it was good. HELP need to pass Ca smog !!

Re: 2003 h2 with p300 code
 

which cylinders are misfiring? if its 7 or 8 could be water in the fuel rail. Could be a bad injector. \if all cylinders on one bank are missing could be a restricted catalytic converter. Could be a plugged injector due to contamination in the fuel system. Could be intake gaskets leaking.

Re: 2003 h2 with p300 code
 

could not nail down witch cylinders are misfiring! the H2 is a 180" limo

Re: 2003 h2 with p300 code
 

Tech 2 will tell you in the misfire history which cylinders are causing the code.