No Cel Or Code. Misses On Highway Then Idles Rough.

[wfu1994]

I have a 98 ES300. I have an intermittent miss that only starts when I am on the highway but it doesnt do it all the time. After it starts to miss on the highway, you can come to a stop and it will idle up and down and it feels like it is missing. If I cut it off it will idle fine or sometimes if I give it gas, it will start idling fine. I have no CEL or codes. I thought it was a coil because I pulled one of them and the boot looked all burnt and like it had been arcing. I changed the coil and it still did it sometimes....also changed the plug of the coil that I changed.....and changed the plug wires.

I am at a loss. I can drive around at 45 and it will not start running rough. It is only when I have been driving like 60mph and up and it doesnt do it all the time. And it smoothes out after it runs for a bit when you get off the highway.

thanks in advance!