Rough idle

Where is the EGR valve located? My2002 Accord EX V6 has a minor rough idle issue and the exhaust smells almost as if it is flooding. I was told to replace EGR valve. Is this correct or do you think it is something different. Otherwise it runs great.

Check engine light is on and rough idle occurs all the time. It runs fine while driving but as soon as you stop, the rough idle is always there. Advanced auto check codes should possible blocked egr passage or random misfire on a couple of cylinders. How do I locate egr if I need to change it also?

2002 Honda Accord with 197,000 miles. Recently replaced plugs and wires. We narrowed down which cylinder was missing: ie (The only one where pulling the wire to the plug didn't make the idle more rough. Pulled that plug and it was dry/not fouled. Replaced all fuel injectors. Finally tested missing cylinder's fuel injector connector signal. It was weak. All other injectors had a strong signal. What should be fixed/ replaced to give a stronger signal to that injector? Do injectors require a certain minimum voltage to operate? I looked for awhile on the message boards but couldn't find this exact problem. Please help. Thanks.

Here is my situation. I purchased this vehicle 2 weeks ago and it ran flawlessly. Engines was very smooth like a new motor. It had 112,000 miles on it and I decided to get a new timing belt and water pump, the typical routine. When I got the car back from my mechanic, I noticed the idle was rough and that it shifted funny from 1st to 2nd gear. I took it back a few days later so he could check it out. He did notice the rough idle and would look at it. He is a great mechanic and a very honest friend and insists he put the timing belt on correctly. I picked it up the vehicle a few days later and he told me that he checked the motor mounts and that they were good. He also did some type of memory check on the car so the cars computer could reset itself. I though this would alleviate the problem. I started it and the RPM stays at 1000 for five minutes then after that goes to 750. The idle is still rough in all gears of park, rev and drive. Whatever he did with the cards computer, the tranny now shifts smooth but the idle remains rough.
I also had him put in new NGK pugs just for maintenance. One more thing. The car almost stalled at a stop sign, gave it gas to keep it going. The car runs perfectly when driving, just at idle does it shake noticeably. Any suggestions?