My 4G64 misfires when it warms up. The first few minutes of driving everything is perfect. Then about 10 minutes into the drive, when the engine temperature is about normal, it begins to misfire and just get worse and worse.

I just replaced all the plugs and wires, but I can't imagine its an ignition issue because everything seems totally fine when it's cold or warming up.

I removed the exhaust before the cat converter thinking the engine might not be able to breathe, and it still misfired.

Any ideas what might be causing it? The temperature specific aspect of it is what's so confusing to me...

it could be the Throttle Position sensor, which is connected to the throttle body, it tells the PCM the opened angle of the throttle body, if the sensor is bad then it will confuse the PCM which takes command from the driver and cause it to think the throttle body is opened and send unwanted burst of fuel to the injectors.

i know you posted this a while ago, u probably already fixed the problem if not i hope this helps. :gitara:

look at other post befor you post they all redy toled other people what was the problem