Ok all you electrical experts
 

Im running a new ground for my pressure sensor and the only ground wire i have is a 4 gauge wire.
Is it bad to solder the 2 sides of the ground wire (which is 16 gauge) to the large 4 gauge wire im using as a ground??

Just to be sure=If you're asking is it ok to solder 16ga to 4ga. A little overkill, but no problem. You wouldn't want to go in reverse. 4ga. to 16 ga. ground or power.

it'll be fine if you can connected them... but connecting them will be hard. you'll need a super hot soldering iron to solder 4 gauge... I would just pick up some smaller wire. not like it costs anything.

oh ok well what i did was solder the 16 gauge to the 4 gauge and bolted the other end of the 4 gauge to the braket for the boost sensor. And yeah it was a pain in the ass getting it to take solder, but i managed to get it to stick pretty well.
Thanks.