couple issues...need verification

well, about a week ago, my GT failed emissions...used a friend's scanner and started fixing some issues with it...i still have a few and i need some verification on what could be my issues. first, i keep losing coolant but can't seem to find a leak...thought it might be the heater core...but last night after doing all the work and pounding on it going home (about a 40 mile trip, coolant was full when i left), it was EMPTY when i got home. i have noticed i get some steam, but i thought it was normal...until now, are there any other checks i can do to check for a leaking head gasket? could a leaky head gasket cause me to have really high Hydrocarbons and fail emissions? also, another problem...i just need verification on a procedure...how do you set the idle on these? i am having a lot of problem getting the idle to go down...it wants to stay around 1,200-1,500...sometimes it will go to 1,000...that is more than a little bit unacceptable...can anyone help?

thanks in advance!
Josh

well, the spark plugs looked normal. old, but normal. i don't recall what the codes were we had...i wanna say 43 and 91? something relating to the O2 sensors. i replaced both of them and checked the connectors. i didn't rescan it after we were done because it was about 5 am (we worked on the car all day/night, just doing different things to it and BSing) and we were both tired...we are gonna hit it again in a few days...

Josh

i will check that out, hadn't yet...thanks man...

Josh