Inconsistent Idle and Check Engine Light

I recently moved from Colorado to Seattle and have been having trouble with my 1990 Civic ever since. After having a 100 point inspection and fixing obvious oil leaks, the car is still idling inconsistently and the check engine light has come on. Is it possible that it's an oxygen sensor problem? In addition, the battery doesn't seem to be holding its charge. I would appreciate any feedback.

Seriously would consider an o2 sensor, probably a vacuum leak or the eacv. Pull up the carpet on the passenger side under the dash and count the number of blinks that the red light puts out in the center of the ecu there. Let us know what it says

The light is blinking once.

just one short blink? Or one long one? and its blinking once, then pausing, then one again?

It's blinking once for about a half second with a several second pause, then blinks again and continues that cycle.

ok, well since you have a d series engine, there are no long blinks to represent 10..so it must be a code 1, o2 sensor

d-series (stock engines in USDM civics from 88-91) obd0 ecus always have short blinks. Consult the FAQ for a list of codes pertaining to the number of blinks. GL

if it's o2 which I think it is, OBD0 computers only read if it's connected or not, not whether it's working right.

if it's o2 which I think it is, OBD0 computers only read if it's connected or not, not whether it's working right.

Please explain to me your theory behind this.

if it's o2 which I think it is, OBD0 computers only read if it's connected or not, not whether it's working right.

This is BS. Test your o2 with a multimeter when the car is running, it should be spitting out somewhere around 0.3-0.7V when warm. You may want to double check that value in a manual.