Replaced original Coolant Tank today and found bent probe and a gunked-up Float on an 2000 XKR > No messages for low coolant after 30 min drive and there does not seem to be any leaks at least up to 55MPH.
However, I am getting a P0442 emissions leak that only occurs below 2/3 tank of gas which clears promptly but did not re-occur after 15 min.
Any direction would help >I have already replaced the gas cap.
Thanks

 

P0442 is a small leak in the EVAP system. Is there a smell of petrol/gas at the front left? Obviously check the line from the fuel tank up to charcoal cannister.
Not sure if Rev Sam's Youtube video is much help for a 2000XKR but could give you ideas. Link below.

 

Thanks David> No Gas Smell is what has me stumped? Other than checking some of the connections at the canister or other side with a possible bad gasket.

 

The EVAP test is done with a Fuel tank level BELOW 80% and ABOVE 20%.

 

Thanks >What does the test confirm? A bad Valve as well as a system vaccum leak? Or all the above?

 

The fuel tank/system cannot 'leak' fumes/vapors into the atmosphere.(except through the carbon canisters)
The EVAP system tests the system for these leaks.