Cold start misfire

Hello Roy. They showed me pictures all the carbon is gone except on the bottom of number six valve compression is fine. They said there were chunks of carbon on the bottom of the valve which is not accessible through cleaning unless the head is removed. It runs much better especially after it reaches operating temperature. It is still rough until it warms up about ten minutes. I noticed it is getting a lot better gas mileage. Now they mentioned possible valve guide or just a chunk of carbon being the culprit. I am thinking for right now to watch it closely change oil regularly, tier one gas. If you were in the proximity I would just give it to you to fix. Have a blessed day, Charlie

Hello Roy. Well I have been driving it and the engine light came on P0420, it is the left bank quite sure it is the catalytic converter. There is also a strong carbon smell inside the vehicle. Mechanic told me to put a gallon of solvent in the gas tank to clear it up a little reluctant to do so. Anyway, I work at Toyota and one of the mechanics is going to remove the heads and install when machine work is done. A friend of mine owns a machine shop told him about number six valve seat said they will go through it thoroughly. Then through rockauto. Com they have a company that reproduces the converter at a fraction of the cost you just send them the old converter. I have not started the process yet does it sound like the only solution. Thanks again, Charlie