so i have a d16y8 with just a short ram and catback exhaust. i was wondering how much of a difference would a chipped p28 make? thanks

 

None.
If you get it properly tuned, then you could pick up somewhere around 15 ponies, but if you buy an eBay chip you'll end up needing a new motor while you're at it.

 

I agree with vegas with the assumption you are using the correct obd2 ecu. if you are running some random program that you know nothing about... get it corrected with a chipped ecu and correct basemap.

all your name brand chips on ebay are serious trash. although there are some programs on ebay that are worth using if you cannot afford a tune.

 

ok so how much hp will i get with a p28 chipped plus tune? thanks

 

Not worth the time. Your setup should be fine on the stock ecu