i just put in a aftermaket meter and i hooked it up right behind the rpm guage in my car and when i get on it my cars reading 7 to 8 rpm and the aftermarket ones only reading 4 or 5.. someone plzzz help.. the one in my car sometimes goes out for a long time so i said **** it and just go buy one but now this is happening

 

Did you wire it correctly for a 4 cylinder car? Mine defaulted as an 8 cylinder I believe, and you had to short out a few of the wires or something along those lines. It's possible (and likely) that it's more accurate than your stock one, but being off 3000 rpm sounds like a wiring problem unless the stock one was really fubar.