My short term trim is running anywhere from -4.2 to 4.8 and my long trim trim is sitting at -7.8 most of the time. Is this normal?

I have installed new cats and 4 o2 sensors. Along with a completely rebuilt motor. I still have a strang smell from the tail pipe.

 

the closer to zero (0) the better on the long term fuel trim. if I remember correctly, -7.8 means you are running lean.

how long have you been getting these numbers?

 

I just got her back together from a rebuild and have only driven it about a month.

 

Well I changed the maf to my original one off the old engien and it now at 0.1