possible problem ?

99 Explorer stalls when I stop. Check engine light is on. Where is the first place I need to look. Engine usually starts back up but sputters bad. I also notice it has been hard to start for the past week or so.... any suggestions on where I need to look. Thanks for all help.

take it to an auto parts store such as Auto Zone and have them plug it into there computer and they will tell you the problem by the read out

Will do thanks for your help...

If you have no error code then it is probably your IAC. It's located at the end of the air intake duct just under the engine cover. It's a small motor with a 2 pin connection and it's attached to a small plunger.2 bolts to remove. real easy. Clean the plunger area. If the plunger won't move you can gently pry it loose with a small screwdriver. I flushed my plunger area with oil and it's been running for a year now. I'll probably do it again before the cold weather sets in. Typically, as long as your foot is into the gas you start/run fine, but when you get off the gas you stall. If the motor itself is bad a new one goes for about 50-60 bucks if I remember correctly.