[IROCdan330]

i'm confused? how does a hole in the y-pipe cause the car to run lean?

I understand he was told at dyno day that his car was lean or whatever from a hole in the y-pipe...but that to me would be misleading. yea, a tailpipe wideband would show lean because the exhaust would scavenge more air from that hole and show more oxygen at the tailpipe...that doesnt mean that his actual air/fuel in the combustion chamber is lean...thats why tailpipe widebands are only accurate with a sealed exhaust system and no cat.

I assume there is more info to go along with his lean condition...definitely would have that carb adjustment looked into.

And Justin, I agree, the combination of everything most likely is contributing to the situation...after those 3 things are handled, we can have a more accurate approach to any cooling issue, if one still exists.