Low idle in drive gears

[TheEagle]

Okay. The title pretty much says it all. In Park and neutral It idles around 1,100-1200 when warmed up but when I put it in reverse, drive, drive 2, or low even it drops down to around 600 RPM's. I am currently not throwing any codes. It sometimes drops a little bit more when coming to a stop and shakes a little bit but nothing truly substantial. It used to be a lot worse until I replaced my battery. What are your opinions?

I will be replacing the wires, spark plugs, and coil soon anyway, but are there other things to check, like the EGR valve?

 

[Lou98GSX]

there should be a label under the hood that gives you your idle spec in drive . if its with in specs and there are no codes then you might have to look at worn motor mounts or exhaust rubbing against something under the car.