1999 Toyota Avalon Low speed miss

1999 TOYOTA AVALON
123,000 MILES • 6 CYL • 2WD • AUTOMATIC
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RCGLFR
  • MEMBER
  • 1 POST
Car has a miss at idle/low speed, seems to go away when you accelerate. CEL codes showed p0300,0301,0303,0305. Replaced plugs and wires. Plugs on rear bank, cylinders 1,3, 5 I believe, were black, front plugs were nice and clean. After replacing plugs/wires car ran better for a few minutes then started missing again and CEL came back on with the same codes. Could the O2 sensor on the rear bank be the problem? It does not show a code for the O2 sensor. Any suggestions appreciated.
Jun 2, 2010 at 1:20 PM
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KHLOW2008
  • ✓ASE Certified Mechanic
  • 41,814 POSTS
  • ASE Certified Mechanic
Hi rcglfr,

Thank you for the donation.

A technical service buletin was issued for misfires due to faults with the injectors.

Try swapping the injectors with the front banks to see if the problem is transferred to them. When injectors goes bad, they might be supplying more fuel than they are supposed and that would result in an overly rich condition and the sooty spark plugs.
Jun 3, 2010 at 1:53 PM
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