O2 Sensor and Electrical Question

[Goldfinger89]

Good morning guys. Ok, I have a 1989 coupe lxi 5sp. I started the car this morning and it stalled right away. I started it again and it ran very sluggish and the check engine light was on. I turned the car off and restarted and gave it a little gas. The car ran fine then. I shut the car off again and checked the ecu. It gave one blink. I know that means it's the primary O2 sensor. I always thought that until the car reached a certain tempature, the O2 sensor wasn't really doing anything until the loop is closed. Anyway, would it be normal for an O2 sensor that is going bad to do that on a cold start up?

Second question. I started my car on Friday night and as soon as I turned my headlights on the radio shot off for about 2 seconds and then came back on. Every time I would apply my brakes the same thing would happen. At the redlights the car was idling pretty low for some reason. Then when I got home and shut the car off everything just died. The interior lights...everything. I turned the key and there was not click, nothing. I turned the key a couple more times and then everything was back to normal. The radio stations were all erased, but the clock was fine. Apparantly something happened that disconnected the power from the battery to the rest of the car. Any thoughts? By the way, the battery light is not on and there is no alternator "whine."

[Dibbs]

Have you cleaned your battery coneections lately? Corrosion can get in there and you can lose contact between the cables and the poles of the battery. You might want to have the battery cables checked too if cleaning doesn't help.

[danronian]

Take off all of the ground cables in the engine bay, clean up the mating surfaces with some sandpaper. That might be the culprit.

[Goldfinger89]

I'll try that. It certainly sounds like either a ground or a worn wire somewhere. Thanks for the advice. I'm really curious about the O2 sensor though. I talked to a mechanic this morning that said the O2 sensor shouldn't be active until the car reaches a specific temperature and then the loop closes and the O2 sensor will start opening and closing. That's why I'm confused as to why the check engine light would come on for the O2 sensor when the engine was dead cold.

[Dibbs]

If the ECU throws a code, it's probably best to go ahead and replace it. You're gonna need it eventually in a car this old. Who knows, your car might run a little better.