96 blazer i have been having trouble with for 2 years...random misfire codes(p300) and(p140) o2 sensor...replaced wire/cap.button...new coil...all o2 sensors...cleaned egr..replaced spider injectors...still get same codes and vehicle really bucks at constant speed and sputters real bad on accelleration....as long as you keep it under a load it seems to straighten out and run better...when relacing the injectors the new regulator has a nipple at the end that looks like a hose should go on...but the injectors i took off was the same way...why is that left open(everything is under the plyenum so you really can't see whats going on..