I know I can make adjustments to change the AFR under WOT with the Power Enrichment table. My question is, I need to lean out my AFR by about 0.4, what would I need to do to the PE table to raise the AFR by 0.5, I don't want to do too much and cause a problem. I can use Auto Tap to check it afterwards and refine it. Then later get on a dyno and use their wideband to refine it even more.

 

To richen, you multiply the PE vs RPM table by a percentage greater than 100%, such as x104%; to lean out, multiply by a percentage less than 100%, such as x95%.

 

Since I need to lean it out a little, I'd be using a % less than 100%, BUT how do I know what percent to change it?? I need to lean it out about 0.4-0.5, so would that be 98%, 95%, 80%, you get the idea. Or is it just a trial and error thing??

 

I would start by leaning it out 3%, or the PE vs RPM table x97%. If your a/f was, for example, 12:1, that would put you at approximately 12.6/1.