Some people only cook with pecan wood and their barbecue certainly does not taste like pecans. You’re being fed some hogwash. Pecan is very similar to hickory but a little milder. It’s some peoples favorite wood and there certainly isn’t a problem using it throughout the entire cooking process.
Pecan is one of the best smoking woods. No, your meat will not taste like pecans. This is basically the only wood I have been using for the past few years. Contrary to popular belief, it is not that mild of a smoking wood and yields an excellent flavor. It is less bitter than hickory, but with a bit of the same flavor, and in my opinion, it is just a tad stronger than oak or apple. Where the idea that it is a “cool” burning wood got started, we will never know. It makes good coals, and burns as hot as any other hardwood in its class.
The woods used for smoking do not give the meat the flavor of the type of fruit or nut the wood came from–almond wood does not make the meat taste like almonds and lemon wood does not give the meat a citrus taste.