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Fix to the CAT to get SMOG passed?

Scotty is like click/clack. They talk about repairs. And why you should buy a 1998 Toyota.

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I got some live stream data while the car was running:

At 2k rpm:

  • O2 sensor output voltage-B1S2 = 0.095 - Low?
  • O2 sensor output voltage-B1S1 = 0.210 (replaced in 2016)
  • Ignition timing advance for #1 cylinder= 33.5 BTDC - high?

At 800 rpm:

  • O2 sensor output voltage-B1S2 = 0.015 - Low?
  • O2 sensor output voltage-B1S1 = 0.115 (replaced in 2016)
  • Ignition timing advance for #1 cylinder= 15 BTDC

manifold absolute pressure sensor = 4.64

When I drive, the downstream O2 sensor fluctuate between 0.02 - 0.88 volts!

Anything obvious?

Just a possibility. You may be running a bit on the lean side (caused by an O2 or intake sensor or even a small vacuum leak) or higher than normal combustion chamber temperatures (caused by aggressive timing, cylinder head/piston buildup, incorrect AFR). Or you could just have a bad CAT like just about everyone has said.

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Spot on. So:

  1. O2 sensor
  2. vacuum leak or leak on exhaust
  3. higher than normal combustion chamber temperatures (caused by aggressive timing, cylinder head/piston buildup, incorrect AFR).

I just completed:

  1. above by following the process below - disconnected the PCV and O2 voltage stopped fluctuating and fell below 0.1 volt - I didn’t bother checking for Rich condition given its NTK part that was replaced in 2016
    https://dannysengineportal.com/o2-oxygen-sensor-function-failure-symptoms-testing
  2. I need to test - but the car idles fine. Also hole in the exhaust could also cause this
  3. Unlikely since no mods were done to the car.

Also cleaned the MAP sensor.
I found a bad PCV valve - its only 2 yrs old! Replaced it.

Me neither. He’s shadow banned myself (and I’m certain hundreds others) from commenting on his videos. If you’ve ever take a look a comment section on his videos it’s comprised of roughly 99% of people who don’t know any better, singing his praises. If you post something criticizing him, and I’m not saying you’re running him down like you’re channeling a mid-80’s Ric Flair promo, but more like “Scotty is incorrect here and here’s objective proof as to why I say that…” He’ll shadow-ban you at the drop of a hat. I think the guy knows he gets alot wrong and contradicts himself often., but doesn’t want to let his less-informed fan base in on it.

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