2001 Toyota Tacoma PO420, CALIFORNIA EMISSIONS

2001 TOYOTA TACOMA
175,000 MILES • 6 CYL • 4WD • AUTOMATIC
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NATEMC
  • MEMBER
  • 1 POST
I HAVE A SES LIGHT, CODE PO420, CHILTON BOOK IS NOT VERY SPECIFIC ABOUT O2 SENSOR READINGS, BOOK SAYS THE O2 SHOULD READ BETWEEN .1 AND.9V, IT DOES NOT SPECIFY UPSTREAM OR DOWNSTREAM. ON MY TRUCK, THE UPSTREAM SENSOR IS READING APROX. 3V AND THE OTHER ONE IS WITHIN THE SPEC IN THE BOOK. THE TRUCK IS CALIFORNIA EMMISIONS AND I DONT KNOW IF THAT MAKES ANY DIFFERENCE IN WHAT THE READINGS SHOULD BE.
ALSO, I REMOVED THE CAT. CONVERTERS AND LOOKED INSIDE TO SEE IF THEY LOOKED BAD OR CLOGGED AND THEY BOTH LOOK CLEAN, ALMOST TOO CLEAN, NICE AND WHITE.
I WOULD APRICIATE ANY HELP BECAUSE ALL OF THESE PARTS ARE WAY TOO EXPENSIVE TO GUESS ON
May 5, 2010 at 6:35 PM
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RACEFAN966
  • ✓ASE Certified Mechanic
  • 5,029 POSTS
  • ASE Certified Mechanic
Ok if you have no exhaust leaks then it looks like the O2 infront of the cat is bad. It could be a mass air flow unit too but not very common. Let me know how it goes
May 6, 2010 at 10:42 AM
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