I'm having a similar problem. Runs terrible when cold, fine when warm. Today I tried connecting the diag terminals when running. SES light shows open loop (2 flashes/second) for a few minutes, then goes to closed loop (1 flash/second). The longer the duration of the flash, the richer the mixture and vice versa, by the way. I am wondering if you are a) Not running in open loop (and thus maybe EGR is open, etc). b) Or running poorly in open loop (like I am). Can you try this for purposes of comparison?

2000 Mitsubishi Montero Endeavor, "Katsumi", 138k
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1989 Isuzu Trooper, "Beniko", R.I.P. at 233k

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