Is this a scam???

My son sold his RV (trailer) and so is downsizing from his F350 SuperDuty to a smaller truck. He had a Tacoma before and wanted another. Priced a Tacoma lately? Yikes. Anyway, he found a 2005 V6 with 210k at a dealer 41 miles away (road distance), inspected the hell out of it (in part using my borrowed Veepeak OBD2 and borescope for the frame), test drove it hard for around 10 miles. Seemed to be solid mechanically, albeit with really chunky and noisy off road tires and a nice coating of clay on the bottom. He scanned it again and nothing. So he bought it and drove it home. Once here he rescans it: P0420 and P0430 pending, no CEL yet. The app he uses said (in our driveway) that it was 56 miles since the codes were cleared. Most likely the battery was just unplugged and all 56 miles were the test drive and the drive home. Cars on lots often have their batteries disabled, that part isn't in itself suspicious.

The dealer has a "return it up to 5 days or 240 miles" coverage. Seems like about the same amount of usage that would be needed to promote the pending codes to an actual CEL. My money is that they knew the cats were marginal/bad but calculated that the CEL was probably not going to trigger within that short usage period. Most buyers are not going to scan for pending codes, they would only scan if the CEL lit.

There are things that can trigger a P0420 and P0430 that aren't the cats, but statistically, that is by far the most likely problem. I suggested he just take it back now, but he wants to have a local Tacoma mechanic have a look at it first.

As an interesting twist on this when this vehicle was made California allowed Federal cats on trucks. Up until (I forget the exact year, 2018?) if one failed it could be replaced with a Federal cat. Unfortunately, when we had the cat stealing epidemic they changed that rule, so that now these old trucks need CARB cats if one is replaced, which are more $$. Just for fun, the vehicle has 4 catalytic converters. Looks like ballpark $2400 in parts to replace all of them.

Thoughts?

Edit: forgot to mention, for people not used to CA laws, it isn't legal to sell a vehicle here which cannot pass smog. Either one of those codes would be disqualifying once they get past pending and trigger the CEL. I don't think "pending" (with no CEL lit) would fail smog though.

 

Son took the truck to a mechanic today for an inspection. Mechanic saw the cat codes (still no CEL but only about 1 mile more on it) and other issues culminating in one big one: no coolant visible in either the overflow tank or the radiator. Son had checked the coolant level in the radiator before starting the test drive and it was full at the time, capacity 10 quarts. 3 or 4 (at least) gone in 50 miles. He didn't check it on arriving back home because there was no reason to - no cloud of white smoke behind it coming back from the dealer, it didn't run hot, and in the morning no puddle under the car. Luckily the mechanic is just 3 blocks away so even if it was completely empty that wouldn't have hurt anything. Anyway, it's going back to the dealer, and they said they will refund, but they won't pay for a tow. Son doesn't want to drive it because the verbiage in the agreement is mushy and if the motor blows for any reason they can argue he is at fault for driving it knowing there was a massive coolant problem. So we're off to rent a car carrier. Luckily he had not yet sold the F350, so plenty of towing capacity in house still.