code 45 ?

I have a 1990 GPSE 3.1L FI 180k
I get a code 45 from it .The o2 sensor is less than 2 months old could it be bad already?I did put some gas from a questionable station (known for bad gas ) .The day after that it quit idling and only runs if I keep on the accelerator. What are some of the possible things I can check ?
Any help would aprreciated .
peace

code 45 is rich exhaust. A bad o2 will normally trip a code 13 (o2 shorted), both code 44 and 45 (rich and lean exhaust) or a code 61 (degraded sensor). I believe the o2 is doing it's job, and you have a fuel delivery or spark issue allowing too much unburned fuel into the exhaust.

Thanks RichTazz, I am running Bosch platinums could that be a part of the problem? Its definately getting fuel by the amount coming out of the exhaust. :O lol