I bought my little Dak earlier in September, and have deliberately been driving the heck out of it. It had been sitting a long time, and I wanted to shake it down for issues.

I then let it sit all week, starting it for the first time since last Saturday. It started slow, and idled REALLY slow for about a minute, then leveled off to a normal mode. The seller said it did that, so I'm not much surprised.

What I am is curious what that means? What might be failing that would cause this? There are no CEL, it passed emission testing, has a brand new exhaust including cat, and has a fresh tune-up. Truck is a V6 with 160,000 miles on it.

Any ideas?