It sounds like you performed some tasks that needed to be done anyway (other improvements despite main issue remaining). You might find that if the ECU suspects that the cat or downstream O2 is failing, it may play with the fueling during low load conditions as a test. Especially on the later models, there are probably lots of little tests and functions that we are not privy to. I am still surprised that a new cat and gasket fixed it.


Corbin
'95 ESI-T

Now with more power and fewer leaks



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