I just today received a CARFAX email about it.
Manufacturer Emissions recall issued
#U67 2011-2016 2.0L - 2.4L NOX FAIL (US)
Status: Remedy available
I bought my 2013 Patriot pre-owned in July 2018 and haven't received anything about it and can't get the "system" to give me any info about it - the CARFAX email gives a hot spot to get a copy of the Owner Letter but the hot spot doesn't work. My oil change is due in July so hope to get some info about it when I get to the dealer then. Guess it must not be too important since neither the dealer nor CFA nor the Fed Recall people have sent me the official recall notice. Like the OP, nano2016, I would love to see what the customer letter looks like. I've sent CARFAX an email asking them to clarify this but who knows if they will ever respond.
2013 Jeep Patriot Sport FWD 2.0L I4 DOHC 16 valve dual VVT CVT Transaxle / Model Code MKTE74 Preowned VIN = 1C4NJPBA8DD164547