When my truck is cold, it backfires very lightly. Just a quiet pop about once a minute. What would cause this to rich, or to lean.

I need a wideband o2 don't I.

 

You can monitor your stock O2 sensors and see where they are. They aren't accurate for tuning, but if you're running rich or lean enough to cause problems it will show.

 

I was going to wait until the engine was broke in to get it tuned, or get hptuners, I can't decide which yet. Can any obd scanner read the stockers, because I know some people who have them.

 

If you've got cat converter light off spark enabled in the tune, then that is the likely cause. In a warm-up condition, the timing is extremely low and in some situations, the mixture will still need a lot of burning to do after that exhaust valve has opened.

Justin

 

So, it's to rich durring warm up. Will this hurt anything, like valves, because I don't want to f-up my new engine.

 

No, it won't hurt anything. I don't think Justin said it was too rich, he just said that the timing is set so low in those conditions that the mixture is still burning as it gets pushed out of the combustion chamber.