What happens when
 

What happens when the check engine light comes on in reference to the fuel
delivery system? i.e. If the oxygen content is too great or defective
(code 1) and causes the Check Engine light to come on, does the ECU just
"guess" from that point until the next engine restart, or what? When the
IAT sensor causes the light to come on, (code #10 or #14 , I think) Again,
does the ECU "guess" at the how much fuel to inject? Anybody know?

Thanx in advance!

Jonathan

P.S. Again, for those of you who may not know, I drive a 1990 Civic LX 1.5L
DPFI 5-speed.