97 nissan quest codes help

You have a miss fire in No 2 cyl, ands a knock sensor fault, check the plug and if coil over plug swap coil and see if miss changes cylinder, if so fit a new coil, if leads change the leads.

mark (mhpautos)

The PO325 is a knock sensor code. That is pretty common in nissans and is usually caused by a bad Knock sensor but likely has little to do with the rough idle.

The PO302 indicates a misfire problem in cylinder #2. This needs to be looked into to determine the cause. You always want to start looking at the secondary ignition components like the plugs, wires, dist cap and rotor. There are many other possibilities but eliminate secondary ignition first.

Injectors are very common. And cylinder # 2 is very easy to diagnose and repair

when i turn off the cel with the obdII scanner the van runs better,but after 100 miles or so it comes back on and its running rough.in my original obdII scan,when i first bought this van a few weeks ago,the po120,po325,po302,and po702,po703 were all lit up,i cleared the codes then and it didnt light up again for like 200 miles with only po325 twice and po302 once.i dont want to do a knock sensor if it is somethging else.could the initial code po120 tps still be the culprit but it hasnt come back on yet for some strange reason?? thanks guys,i am a girl and need all the help i can get,im alone on this one..

You can't just ignore codes and hope they aren't effecting anything. You have to work on clearing each code and see what you have left. Continuing to just erase them isn't going to fix anything either. You're erasing all your freeze frame data every time you do that.