Nissan Repair: missfireing in 1 cylinder, exhaust leaks, nissan maxima

Question
I have a 92 nissan maxima it has what seems to be a exhaust leak when I first fire it up, but after about 5 minutes it goes away but when it warms up for a few more minutes it has what seems to be a miss like im loseing a cylinder and idels very rough.

Answer
Duane,

One or both of the manifolds is probably cracked or has broken bolts.  This causes exhaust leaks and freaks out the oxygen sensor.  I would correct the exhaust problem first and then clear the code.  If it still has idle issues I would complete a tune up that included plugs, wires, cap and rotor.  But, my first thought is the exhaust problem before it causes other problems like warped exhaust valves.