Code P0156 and P0442 related

[Chuckaz]

1998 4.0 SOHC 4X4 138k miles

I recently changed:

Thermostat housing (leaking very badly)
Plugs
U-Joints

Since the Thermostat replacement the coolant level has remained steady and the "strong" coolant smell is gone, but I still have a slight odor when the truck is warm. I would think that if it was the intake gasket it would have some coolant loss? Could I have bumped the O2 wires while working on the U-Joints? Is P0156 the code given when the intake gasket is leaking?

Could these codes be related or do I troubleshoot them separately?

I need advice as to where to start on this.


Thanks

 

[jremington59]

The first one is most likely a bad O2 sensor on the drivers side behind the cat. The 0442 is an evap leak. It could just be the cap or there is a small leak somewhere in the fuel system.