I just purchased a 1996 e 320 and and it had an egr valve problem, which i got fixed. What i noticed is that after getting the egr valve,the spark plugs, and the air filter replace by my mechanic, the idle on the car cjanged some what. You see prior to getting all this work done, the car when first started in the morning would idle about 1000 rpm and then within 30 seconds it would drop to the normal mayde 600-700 rpm. Now that i did the repair on the car, when i start the car the rpm stays at about 1000 for 2 minutes, afterwards it drop to about 850-900 and it stays there, it will only go down if the car is is driven. My mechanic said that is normal, i'm not sure if he is correct. I thought i'd ask for your opinion.
Should my cars idle go down right after its started. Your opinion please?

Thanks