The first set of codes were for the NSS and the Throttle Position Sensor which the NSS was cleaned & adjusted, and the sensor was replaced. After that the check engine light went away, my reverse lights now work but slowly she started having a hesitation when starting which is now constant. I went to check for codes even tho the check engine light wasn't on and i got a 700, 705, 442, 121, and a 122. I know the 700 & the 705 are for the NSS and the only thing i can think of is put the new one in that i have on deck. For the others, ive checked most vaccum lines, my gas cap is on tight and i cant figure out what is still causing those codes.

Any advise on what to check for or what to do would be a big help!

 

assuming you we are talking about OBD II faults on your 1998 Cherokee
P0442 is a small evap leak. Most likely a cracked vacuum line around the canister area, or a rotted line going to the tank.other causes could be a sticking canister Vent valve, a purge valve.Gas cap, Filler neck, fuel tank. Sometimes a Smoke test is the only way to find a leak, unfortunately most people dont have access to a smoke tester.
P0121 - MAP sensor and TPS dont agree with eachother.
P0122 - TPS Signal too low.
for those two it's entirely possible that you have a vacuum leak that you dont know about or that one or both of those sensors have failed or are failing, which would not be uncommon given the year of your car. I would check all vacuum lines again. Did you say you replaced a sensor? which one?

the trans faults (the 700s) is more than entirely likely that you have a bad NSS I would replace it.

 

All of those codes are the same one I had, turned out to be the #10 fuse on the interior fuse panel was blown. Its a 10amp fuse. Dont know if this will help.

 

Smoke machines are expensive. Buy yourself a $40 fog machine from Walmart and some hose to hook it up to the vehicle of your choice. It does the same thing as a smoke machine that costs over $1000.