If you had this before the tune then defiantly something is up.
I would be curious about injectors being dirty at that point. Might not be to bad of an idea to run some kind of injector cleaner through the system.
I agree to monitor on the stock tune. If the symptoms carry over but not as bad then the tune is partly to blame. However I again agree you may have something more going on here.
Originally Posted by 09HemiCrew
Thanks, I should probably put it back to the stock tune and do a little monitoring to see if it is similar with the knock/stumble. I just couldn't NOT install the tune when I got it... It definitely feels better performance wise, but this stumble is really bothering me. I will have to try it again with the MDS turned off and stock tune to make sure I am not just getting knock because of the 87 canned tune. The stumble feels the exact same as before I had the tune installed and the two cylinders that appear leaner than the rest have me thinking something else might be up. But, who knows...