are you supposed to tune, if you have a exhaust leak? one of my exhaust manifold bolts seized and i had to break it off, so now theres only 2 boltson my exhaust so i know its leakin

 

you can tune it but if you going to fix it sometime soon . i would just wait

 

I have a slight leak as well. I tuned the motor anyway, what the heck. I don't think it leaks enought to throw off AFR readings.

 

AT WOT I noticed that AF reading were not that far off (best guess about .01-.03 off) during partial throttle and idle they were way off though and should not be tned with. fix your leask, and get it tuned properly if you can do Partial throttle

 

That's true - a leak at the exhaust flange is worst at idle when the exhaust gas has a low exit velocity.