ok 1990 4.0 cherokee idles super low almost 300-400rpms, ive replaced the IAC and TPS but to no avail. what else can it be?

Also ive got a oil leak by the back of the oil pan that im trying to figure out, the oil is leaking from the oil pan gasket i think . it is dripping from the lip of the pan in the rear the previous owner just replaced it but he waas no mechanic to say the least, nothing from inside the inspection plate side. only 150 k miles on the jeep. any ideas?

 

my 92 4.0L had a leak that looked like it was coming from the oil pan gasket till i cleaned it all up and ran it for a while and traced it back to the oil filter mount housing(not sure technical term but sounds good)