'95 Grand AM 4cyl has a problem at start up from cold. After two to three minutes the idle will stumble and then go high several times. Some times it will die some times it will recover. It will run fine until the next cold start. This is worse in colder whether. According to the scan tool it happens just after the computer goes from open loop to closed loop.
I am thinking that this happens too soon for the O2 sensor to be properly heated.
Does any one know what tells the computer to switch to closed loop?
What should the voltage be for a cold O2 sensor?
Thanks, Scott