95 1MZ Emission Test Fail

[ErikS]

Failed emissions two years ago, the “certified repair facility” flushed fuel injetors, changed O2 sensor (didn’t say which), retest results worse – took a waiver.

Up for retesting now. Cleared P0420 code by installing two new Denso O2 sensors on Bank 1. Emissions test failed - high HC (Nox and CO OK). Since I took the waiver 2 yr ago, the car must pass emissions now.

Bought ScanMaster software, but need help in understanding the results. The car is running great, so I hate to tear into components blindly (I have service manual). Plugs were last changed 65,000 miles ago, along with fuel filter. New CAT a little over 40,000 miles ago (exhaust pipe rusted) – a year before the last emissions fail (is my CAT dead?). Indiana law allows for OBD-II ‘testing’ for cars ’96 and newer, but ’95 and older must be tested on the rollers with tailpipe testing.

On filling up the gas tank completely, gas odor is strong in car. Fill pipe seems intact, though rusty, so maybe there’s a hole somewhere on top of the tank? Could this cause a HC fail?

Would appreciate hearing suggestions for what to fix first to get the HC readings down.


Fail Report from Emissions testing (top graph is HC):



Scanmaster results:
System Status:


O2 sensors at both idle and 2500 rpm:




2500 rpm live data:


Idle live data: