the car runs great when u first start it up but after about 10 miles of driving the car goes to missing and sounds like its running on 4 cyl. its getn the fuel because the un burnt fuel is popin in the exhaust. a local mech. said it was the opti but i wanna get some opions on here thanks

 

o2 sensors

 

most likely plug wires. my car was doing exactly wat you're saying and i changed my wires and it stopped. i did also change the o2 sensors but that wasnt the problem.

 

How do your plugs look?

I had sorta the same problem, but im batch fire, my whole drivers side bank stopped firing. I got a noid light on it and found the problem to be a bad connection at the PCM.

 

Could be problem going into closed loop after warmup, but 10 mins is sorta long. To eliminate O2's unplug them an see if it runs OK in open loop. Otherwise get it scanned for codes and suspect opti, wires, plugs.