Steve74-02

2002 Z28, LS1, 6spd. 65,000 miles...here's the story.
The SES light came on steady and then was flashing. I got the codes:
PO200 Inj Circ Malf (even though it sounded like all the injectors were clicking on-off),
PO300 Random/Multi misfire,
PO155 O2 bank 2 sensor 1,
PO161 O2 bank 2 sensor 2.

I was away for a week and when I returned the battery was dead. So I had to replace that. SES no longer on. Car seems to be running better, but still a bit rich I think (I brought it up to operating temp and drove about a mile).

I called to bring my car in for service (chevy dealer) and they told me they can't diagnose without the codes - I need to drive the car a while to get the codes back. I told them what the codes were and that I could tell I'm running rich. But they won't touch the car without the codes.
So the questions are:

1. are the codes really 'gone'?
2. how many miles do I have to drive to get them back?
3. will this cause any other damage?

and would a low battery affect the PCM? or cause codes to register mistakenly?

2001NBMZ28

Yea they're gone - do some driving. www.obdii.com/drivecycle.html

Steve74-02

I ran the cycle as described in the link. I've done it 3 times. Still no codes returned. The car seems to be running fine. (as opposed to before i replaced the battery when it was running rich).
Can a low battery/charging cause the O2 heater codes? I know when it happened it was a damp cold day and I probably had the heater/defroster on along with the lights and fog lamps.