5
questions

I'm not getting check engine light or any codes. New plugs have been installed & injector cleaner used. Any ideas ?

Lights all stay on all the time

ABS, Brake & anti-skid lights all came on and won't go off. All 3 came on at same time. Tried resetting computer but that didn't work. Still drives fine.

It usually comes on after about 15-30 miles. If short trip it will not come on.
This last time it came on and will not go off
The air pressure is fine in all tires including the spare.

Further, I have a gas cap indicator light that has been on for a week or so. What is that? Are the two related?