I need help with the process of tuning the MAF on my gen IV 5.3. I relocated the MAF to a new housing when I built a custom intake tube and now my tune is all out of whack. Did not initially realize that the diferent MAF housing diameter would change the air flow tables as much as it did.

 

Forgot to mention that I am using HP tuners. I was thinking that I neded to log fuel trims vs. maf error, but I am not really sure how to go about doing so.

 

Do you not have a wideband?

 

A different MAF housing will cause a massive change in fueling. Multiply the MAF table by the ratio between the new MAF housing cross sectional area vs old area. That should get you started.