Looking for some advice guys. I just got back from Niagara Falls ( approximately 100 mile trip) and my 05 TL now feels like it has a misfire on idle but no codes. I'm hearing a intermittent popping sound out of the exhaust but only after it"s warm. I let the TL cool down for a few hours every thing is normal but once I do a highway run and than get off the highway the popping returns.

 

The ecu doesn't detect a misfire, it monitors forward movement after the firing of each cylinder and if the engine doesn't respond the
same as other cylinders, the light comes on, if nothing seen, no light.
Just a quick guess, take a look at the EGR valve to start.

 

No codes? Does that mean that you took it someplace to read the codes?