Hello i have a 2003 H2 i have code po300 i took it to shop they told me to replace two up stream o2 sen and fuel cleaner so i did still po300 i then changed spark plug wires and pvc and still same code now i have code po101 also i replace mass airfow cencer and still same codes can any body tell me how to get fix thanks Darnell

 

from a quick Google search

OBD-II Trouble Code: P0300 Random/Multiple Cylinder Misfire Detected

Ross

 

Do ever hear any detonation when going up a slight incline or when opening up the throttle? Sounds to me like tuning issues. You can try disconnecting your battery and cleaning your MAF with electronics cleaner found at the auto parts store(spray can). Let it dry overnight on a heater duct and hook it back up.

 

How many miles on your Hum? Those engines are bullet proof. Injectors usually throw codes when dirty. They tend to make the vehicle run too lean and misfire. Ive noticed two cans of seafoam to a full tank is as good as injector service. Some of us backyard mechanics can diagnose when a mileage number is reached.

 

Just started getting the same code on mine. Driving on an incline pulling my cargo trailer is the only time it does it.really don't feel anything just see the light come on.

 

I had that issue with mine. It was a bad plug. I suggest replacing all your spark plugs and see if that corrects the issue.