2003 NIssan Sentra 99500 miles .Car jerks when at stop light. SES light is ON and SES code is P0302 Cylinder 2 misfire. Probable causes vaccum leak, air leak, mechanical fault. What is wrong?

Is going to the dealership for pinpoint diagnosis a good idea?

Verify the spark plugs and the harness first. It's easily done yourself. You just need a ratchet and a 5/8 spark plug socket. After that, you can look at the egr passage. It may be clogged up. If one of these is not the cause, then move on to more complicated hypothesis like the leak. IMo, going to the dealership for a 10 yo car is too expansive. If you want to get the job done, pick a place you can trust. I don't know how much it costs elsewhere but here in Canada, dealership mechanics are usually 30% more at least. Sentras are not complicated cars, you can get the job done anywhere.

Thanks for replying, really appreciate it. I will take it to a local mechanic but is it ok to drive it a little till i get it to the mechanic or will that worsen the problem. Also is there a way to be sure that changing th spark plug or unclogging the egr fixed the problem for good or do i have to wait till it starts acting up again.

It's not good for the engine to "jerk" but you can get it to the mechanic without problem. Keep your engine revving when stopped at the lights by giving a little bit of gas at neutral. Since you seem to be going to the garage, you don't need to worry about what is the issue. They know what they're doing there. Be sure to ask an estimate before they do the real work.

Thanks again. Your replys have been very reassuring.

the car hasnt give me any trouble in the past 3 days and the SES Light is NOT on either. the mechanic said there wasnt anything to fix and to bring it back when it started to give me trouble. What do you think? Please let me know.

CAn someone please advise as to what i should do?..Should i let the car be if its not giving me trouble at the moment and the SES light is NOT ON.

One of the causes could be a relay, wire or harness that has a false contact (broken wire). The best thing to do in your case would be to wait for the problem to come back, like the mechanic said since it's hard and costly to diagnose if it's not happening.