Toyota Repair: 2000 Sienna XLE - Low Idle, trouble code, remote starter

Question
I just brought this van (77,000 mi)just over a week ago and two days ago the engine light came on and the idle speed while stopped dipps low and the engine rumbles as if it might stall. I saw a previous similiar question about the 4 runner, but thought I would ask about the Sienna. It was a certified and the only repair was having new tires put on. Also, the van came with a remote starter that I did tried a few times; not sure who installed it. Are these safe to use and could it be part of the problem? Thanks and Happy Holidays  

Answer
I don't know why the check engine light came on, unless the diagnostic trouble code is retreived from the computer and you let me know what it is I can't help, since it it a certified used vehicle I recommend that you take it back to where you bought it and have them fix these problems.