Quality of cheap O2 sensors

[brianl703]

quote:

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Originally posted by kevm14:

My question stems from seeing a table in Tunercat (a popular ECM/PCM recalibration utility for GM cars and trucks) that claimed to be an AFR adjustment for closed-loop. It confused me as I thought narrow band O2 sensors worked only around stoich.

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That's true, but once the computer has learned from the oxygen sensors where stoich is for the particular engine it's controlling (as all are slightly different due to wear, vacuum leaks, sensor tolerances, fuel injector clogging, etc) it can use that data to calculate out non-stoich AFRs for that engine.