Thread: 2000 Sierra 4.3, P0300 No power
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Old 04-20-2007, 05:46 AM
maxwedge maxwedge is offline
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Re: 2000 Sierra 4.3, P0300 No power
Welcome to AF. Try disconnecting the exhaust in front of the cat, or check the temp in front of the cat vs the outlet, should be 100 degrees difference, if not it could be bad. Also 65 psi is the desired fp. If the vacuum drops way off under load the cat is usually bad. Does it misfire at idle?
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