That last few times I have had my car tuned on the dyno it was acting funny. First off my setup was 6.0L patriot stage 2 heads, 60lb injectors, comp cam .581/.595 lift, 230/232 duration, 114 lsa, LS6 intake. Anyway both times we will have it cruising on the dyno at around 2,000 rpm and it will be the right a/f then just go rich all the sudden for no reason. And will just be sputtering, not horribly bad but enough to notice. baaaaaababaaaaababaaaaa haha if you can imagine that. Just trying to figure out what could be the cause before I have it tuned again after my cam swap. Also did seem sluggish just reving it up off an idle in nuetral, and low rpm seemed very sluggish until it hit around 4500 plus rpm. But that could also be the stock 3:23 gears. Any ideas?

 

Check your O2 sensors .

I had one that took a **** after going though a puddle of water.

The car ran the same way. It would idle fine and run in power enrichment fine, yet cruising would run like **** . Put my HP Tuners scanner on it and Boom, seen that it was not toggling.

 

Is your tuner not scanning it while it's running on the dyno? If it's going rich, there should be some evidence of the cause in the scan data. Same deal with the hesitation. There should be evidence of why in the scan data.