| Check this out: -new o2 sensors
-new cats (i'm now positive there are no pinhole leaks before cat)
-new plugs
-seam foamed twice
-injector cleaned once
-checked timing
-cleaned EGR entirely with snake
-new radiator and cooling system top notch
-water pump pulley for the aftermarket crank pulley
-pretty sure valves are good
anyhow, what I'm suspecting is there's a leaking injector due to a black spark plug, which is on the same bank as the smog sniffer (left). The excess carbon is fouling the plug, which is not completely firing. While this makes carbon monoxide for the nox to bind it's o2 molecule to, it also let's oxygen and hydrocarbon though. This oxygen reaches the cat and doesn't allow the nox to split and be stored...and I assume not enough CO is created either. Anyhow, the HC and CO are cleanly burned in the cat resulting in low HC and low CO
(good), but oxygen is still somewhat high and of course nox is ~1200ppm at 15 and 25mph.
The strange thing is the oxygen levels were sometimes different on each smog test, some really high at 4% and some at normal levels >1%. The little putt putt noise at idle tells me there's a misfire going on and with regards to the snippet I posted earlier regarding misfires and an increase in nox it's pointing me in that direction. What's funny is there's not much theory on this idea other than a Magnaflow tech bulletin and a Toyota Motor Sales training manual.
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