fault code PO300 - 01/02 & 02/02 ?????????

originally i had three faults PO300-1/3 PO335-2/3 PO341-3/3 I REPLACED THE CAMSHAFT SENSOR THEN I GOT PO300-01/02 AND 02/02 WHICH INDICATES MISFIRING I AM GOING TO REPLACE THE SPARK PLUGS SINCE IT HAS BEEN AWHILE SINCE THEY WERE CHANGED. THANKS FOR YOUR RESPONSE . IT WILL START WITHOUT HESITATION RUNS ROUGH AT IDLE HAS NO POWER IF YOU TRY GOING UP A SLIGHT INCLINE AND DRINKS THE GAS . TOMT

Blazer with the 4.3.... Pickup with either the 4.3 or 2.2 ???

IT'S A 2.2 LT

It has 2 oxygen sensors, sensor 1 is in front of the catalytic converter....sensor 2 is behind it... Keep in mind these sensors see a problem with air/fuel ratio and it does NOT mean they are defective!!... It is too many possibilities to guess at the actual problem... A professional scanner will be needed to help diagnose this trouble!.. Not a code reader but a real scanner!

thank you very much for this information and for direction to resolve this issue tomt

U're welcome