Chihuahua crate training help?

He urinates good outside but holds on to #2 and wants to do it in the house. why is he doing this? eventually I have to tie him on the long leash outside then he does #2 there. Prior to that he was going all over the house and ds driving me crazy. I just got him 2 months ago and he was born August last year. I was told he was trained but once he got here he started roaming freely all over the house and marking his territory. The smell really bothered me and I had to mop and disinfect the house frequently. I work different shifts. but when I am home I took him out frequently and he would not empty out completely, he would hold some in to do inside. He only did #2 once (the first day he came, then never again) he would do it inside in different spots around the house. I bought expensive sprays to train him out, all useless. I bought a tray and pads to put on bathroom floor, he defacated there sometimes, he would be praised and given a treat,yet he continued bad behavior.