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!

PFB

You probably do have a code stored in memory. A code reader will retrieve it.

wfu1994

mechanic hooked it up to his computer and found no code......thanks

Gerson

iTrader: (1)

Maybe one of your coil packs is failing but not enough to store a code on the computer or a fouled spark plug. I had a similar issue on my family's Sienna and lastly the check engine light came on the same day I replaced a new coil pack.

wfu1994

Very strange because now after changing the coil, it rarely does it but will do it every 3 or 4 days. When I get off the exit and put it neutral and give it gas, it will idle and run fine. Who knows.

PFB

You probably did have a code in memory, but it erased itself shortly after since the problem corrected (at least temporarily). By the time your mechanic put a scanner on, the code in memory was gone.

Best thing to do, is to buy an inexpensive (basic) code reader, and read the codes yourself immediately when the problem recurs.

Phil