I have a 2004 Altima with 194,000 miles. Normally it runs like a gem but lately it has been giving me a headache. We just had the spark plugs and serpentine belt changed due to maintenance issues. No other issues came back on the diagnostics. I do a lot of long distance driving with the car and as I said it runs great. Within the last two weeks it has been idling rough with stopped at lights or in traffic and it has stalled on me twice. Luckily I have been able to start it back up and then drives fine. Any ideas are welcomed.