Since it is shifting in all the gears and no codes come up when you have the trouble codes scanned with a ahbnd held scanner, Advance Auto or Auro Zone will do this for free. A CEL does not have to show to have a trouble code.
Next check the fuel pressure. Both the auro parts stores I mentioned have fuel test kits with adapaters on an on loaner basis.
The next thing to check would be the Idle Air Control Valve, IACV. It regulates the idle and keeps it steadu under different loads. If the fuel pressure is good and the fuel pressure regulator tests good by coming up to spec without vacuum line on it, the IACV is the next things to check. With the car running, duisconnect the electrical, sometimes vacuum, connector that controls it and see if it has any affect on the idle.
Let me know how it goes.
Wednesday, January 4th, 2012 AT 1:43 AM