Installed Custom X Pipe Exhaust and Now Engine Overheats

Hey guys! I'm a little stumped on this one. It could be a total coincidence, but let me explain what's going on.

So on Monday I had a custom X Pipe exhaust installed using my Jeg's 2 champer knock-offs on the Duster. The exhaust is dumped before the axle. It's pretty loud at idle, but sounds great when cruising.

I don't know if it's at all related, but now my engine overheats. Is that even possible that an exhaust upgrade could even affect engine temperature?

Before the dial would barely get past the second line, and now it goes like 3/4 of the way. When the temp gauge is at 3/4 and I drive it steady at about 40 to 50 MPH, it cools off a bit to half. I did this at night.

I'm running a 26" Aluminum 2 row radiator and a viscous fan clutch with fan.

My guess is that the X-Pipe is so efficient at scavenging that now I'm running so lean it's causing the engine to run hot.

Or....maybe my temp sender or temp gauge is faulty. Maybe the thermostat is faulty. Heck, I don't even know if I have a thermostat actually.

What do you think?