I have an '03 Jeff Gordon Signature Series Monte Carlo SS.

1. I'm losing refrigerant rather quickly. Is there a fairly common cause?

2. After a recharge the air was warm on driver side and cool on passenger.
Are the heat/cool doors vacuum or electric on this model? Are they
adjustable?

Any help greatly appreciated....

 

1. - You have a leak in the cooling system. Some shops can charge the system with a dye and use a black light to find the leak. A common issue is the condenser in the front of the car because it gets hit with a lot of road debris. I just changed mine on my Monte (not hard to do) and once I finish a few more things, I'm going to have a friend charge it at his shop.

2 - I believe in the '00-'05 Montes the earlier years were vacuum and the later were electric. My '04 is electric (with actuators on the various doors). Not sure when the change was made. I actually had the same issue with my Monte. At one point I had to rip the entire dash out to get to the HVAC module and change my evaporator core. While I was in there, I found the flapped used to control the amount of heat/ac to the driver side were a bit "tight". They did not move very freely, so I don't think the actuator was properly able to control it. I used some sand paper the sand down the pivot points (so they were just a hair loose) and used a thin coat of vaseline as a grease on those pivot points. I seems to be working properly since I did that.
It's a BIG undertaking to rip the dash out. But it can be done if you take your time.
I'm hoping my fix is NOT a common issue (The few times I hear about this issue, it's a failed actuator).

 

The actuators are electric. Had the same issue on my 03 SS that I use to have. Blow cold air passenger side, Warm on driver side. It is a little of a pain to swap out but can be done.
I changed mine with a ac delco part and took me 30 minutes. But I am mechanic and have the tools to reach up in there.
My car I took the cover under the column off, the plastic spring loaded one, also remove the other cover that bolts on underneath, then there was a metal bracket needed removed and you can see the actuator up by the tunnel. 1/4 inch drive sockets with a wobble head or a thumb wheel ratchet are the way to go just FYI.
If you do decide to change it, be sure women and small children aren't in ear shot, because I'm sure a few explicatives will fly lol. It's not hard just aggravating as all heck