P0300 Code

2000 CHEVROLET BLAZER
128,000 MILES
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KEB23
  • MEMBER
  • 1 POST
Truck runs rough, we've done everything from changing wires, and all. Checked all hoses, checked intake valves as well. My fiance is a mechanic and he is stumped, he has no more ideas left to try and fix this issue. It doesn't run rough all the time there's days it runs smooth, then there's days after it rains that it takes awhile to crank the engine up. I can rev up the RPMs and the truck just won't move, when it finally goes it****** until you get the RPMs up and hit about 50mph. Took it to a Chevy dealer and they ran tests told me to get the EGR valve and fuel system cleaned. The EGR valve was cleaned and put back, still have the issue. What can we do next? Everything I'm reading about we've done and it still runs bad.
Aug 29, 2011 at 12:59 AM
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RASMATAZ
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 75,992 POSTS
P0300 Random Misfires-Normally caused by vacuum leak and bad fuel.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

1.Defective spark plugs
2.Inadequate spark/coil,defective spark plug wire.
3.Lack of compression
4.False air leakage.
5.Faulty fuel injectors.
6.Insufficient fuel pressure.
7.Contaminated fuel.
8.EGR valve that is leaking.
9.Oxygen sensors.
10.Throttle position sensor.
11.Manifold absolute pressure sensor
12.Mass Airflow Sensor
13.Idle air control valve

Note: If it doesn't apply disregard it-
Aug 29, 2011 at 1:07 AM