Should I back out?

Purchased a 2014 TDI. It was newly traded, no fix yet, really dirty.

Leaving town at the same time, they said I could come back and get it all clean and with the emissions fix.

Signed everything but held my trade title based on my final inspection when I return.

I have a 3,000lb RPOD camper. My main reason for the T3.

After reading everything about how the fix effects MPG slightly, the shift points and hunting for gears.

I am really thinking of backing out....really torn on what to do.