Idle misfire

2007 CHEVROLET TRUCK
100,000 MILES • 4.8L • AUTOMATIC
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CHRISTINE ROTH
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  • 1 POST
Truck has P0300 code.
What is causing misfires on one, seven, four and six?
Jun 16, 2017 at 2:51 PM
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SATURNTECH9
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 30,869 POSTS
If the miss fire is only at idle then I would be looking for a vacuum leak.
Jun 18, 2017 at 7:58 AM
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SATURNTECH9
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 30,869 POSTS
https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge
There is a guide how to find a vacuum leak.
Jun 18, 2017 at 8:00 AM