5.7 vortec '00 runs way rich slight rough idle NO CODE!!!!

So I bought a '00 gmc k 2500 slightly rough condition poor maintenence been replacing parts left and right. So lately after replacing sparks plugs adding larger air intake replacing oem mas and intake temp sensor I noticed she was running rich no real power loss and not showing cel. Then bout 2 months ago lost some power pulled the cats and the guts are fused so pulled them entirely and replaced with straight pipe now I regained my power but I really smell gas now ....and huge kick idle isn't to bad lil rough probly cus I need it timed but what can I do to lean it out? Or is there something I'm missing?