if u get a GOOD aftermarket tach with different cylinder ratings such as 2,4,6,8 u will not need a tach adaptor... the neon pcm only shows two cylinders firing because it reads 2 cylinder per curcit. so if u get a tach with a 2 cyl. rating u will not need anything to have it run correctly. but if u only have a 4 cylinder rating it will read HALF of your accual rpms.

 

ok thank you, well mine has 4,6, and 8 cyl... would that mean that I need the adapter(or get another tach)? cause I have a friend that would buy it off of me and I could get another one(a better one).

 

*update* So I need to get the adapter or a new tach, wiring through the pcm with a sunpro is impossible.

Source: Sunpro tech service

 

^ that is correct.... my sunpro tach was kick ***, but it had a 2 cylinder rating on the back, so at the flick of a switch it was reading correctly. i would say get a tach with a 2 cylinder rating, unless u love the tach u have so much then spend another 60-80 dollars and get an adaptor.