2000 sl2 need help please

ok i have a 00" sl2 it starts up fine cold start an runs fine agin cold once it gets to temp is when all the trouble starts, it starts with low idle the loss of power to trany has a hard time shifting when at temp had a check eng light for upstream o2 sensor replaced it today with oe type code light is now off but still having same prob, did a tune up on it about a week ago (wires, plugs, air filter) please don't say its a trany issue as i don't have the cash to get a new car any help would be great its a good car only has little over 100k miles

ok i thank i have found the main issue found out the plugs are gitting wet looks like water could this be from the head?