I have a 93 Land Cruiser, and I noticed that the engine light comes on the first start-up of day when I start to accelerate, but if I shut the engine off and turn it back on immediately then the engine light goes away even when while accelerating. Has anyone else experienced this?
You're going to need to pull codes.
My guess is some sensor is getting tired and not providing the correct feedback voltage when cold, but when warmed up its happy.
The only way to know which one is to pull the code.
My front CAT heater circuit pulls this stunt. Likes to be packed in mud, when clean it throws a code....tried half a dozen times to fix it, and gave up.