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.
You can buy aftermarket ones for way cheaper and weld 'em on. But first, give the engine a tune up and a fresh tank of gas to be certain this problem is a problem that is truly fixed with cats and not something else. Also, every time I see a near new Toyota Tacoma I get sad and wonder how such a perfect, small long-lasting truck with great MPG turned into a huge gas guzzling box of ugly with large amounts of known reliability problems. It's like everything that made their historic pickup truck the greatest truck ever is now that exact opposite of what they're selling. Most embarrassing of all is how weak these rigs are for towing or for truck campers / cab over campers.
