I apologize for asking being how I'm sure this question has been answered a million times on here. months ago I asked this same question. Thought it was fixed but not anymore. With no accessories on such as headlights and a/c will drop in idle real low especially if like at stoplight and holdn the brakes. Otherwise ship shape. I use the bosch 4 sided plugs and keep engine maintained well so I thought. The first time I took IACV off and cleaned it a lil and it right back at it again. If anybody has seen a situation almost exactly similar to mine I thank you for your help upfront.