5.7 HEMI VVT in Ram 1500

if you can take it on a test ride without the owner, go on highway and try and go WOT and run all the way up the RPM range. If there is a misfire due to bad cam/lifter it will set off the CEL. That's the biggest issue with this motor. check oil pans as they might rust through at that mileage. I bought mine new in 2010 and have 207k on mine. ask if you can start the motor from cold, if it has a ticking sound that goes away within a minute or two, it's more than likely got a broken manifold bolt which is fairly common also due to slight warping with the manifold.