having problem with lean on a 93 camaro

hi i'm doing this on behalf of my brother. He asked to look up for a problem he's been having with lean ever since he installed new headers. now i have no idea what that means if anyone has any info on this or how to deal with this that'd be great.

lean is when there's not enough fuel mixed with the incoming air entering the engine. (rich is when theres too much fuel)
is the check engine light on, or is your brother just assuming the engine is lean. headers rarely reduce enough back pressure to cause a lean condition, although it is possible.

there's quite a few things you can do to solve this. i'm not sure if the 93 ecm had a removable prom, but you can have custom burnt chip, or use a programmer, whichever your set-up is. You can get an adjustable fuel regulator, or bigger injectors.

you may have a bad o2 sensor causing this too.