still have a miss

Very unlikely. You would get a code with bad coil. Regular coils should be ~1Ohm on primary and ~10kOhm on secondary. Not sure if that applies to COP, but you can measure all 4 and see if one is different.

Did you look at spark plugs? That should be #1 thing if missing. You can also try to see if there are sparks in each plug the old way or using a spark indicator.

What have you checked so far?

 

There was an interesting discussion a couple of weeks ago from a guy with a 2010. Missing, bad operation, you name it.

Turned out to be a clogged EGR system. I never had a clear idea of what the guy was talking about (no pictures), but it appears that once the valve cover was removed there's this place where the EGR valve goes and a bunch of small channels of some kind all around that spot. It was all filled with a gunky, tar-like substance. Once he got in there and cleaned it all out, his car ran Much Better.

There was some commentary that this clean-out wasn't in the list of recommended maintenance items as published by Toyota, and I think at least one more person saw the same problem. Maybe this is happening to you?

KBeck

 

This is clearly a possibility. This is why I mentioned the EGR in the initial thread opened by tv4fish. I'm not sure why he opened this second one instead of continuing with the first one. Maybe he didn't like the advice offered in the first one?

 

Thanks for the update. How did you diagnose it?

 

The reason your weak coil did not set a code is that the miss was not frequent or long enough in duration to meet the DTC threshold. I have never had a weak or bad coil on a Toyota, nor do you hear of it often on this site, but they are common on Fords, VW-Audi. I had a number of weak coils on Fords I have owned which is how I knew that was the most likely cause of your problem based on your description of the classic symptoms in your first thread. Congratulations on persisting in getting the problem fixed.