Which one of these adds more power, etc. ? I know the Greddy is louder.

 

for power neither are going to give you a decent power gain alone...
i like the a'pexi. it looks really nice and has a nice tone to it... the only problem i see is if you have a 97-99 max because you are going to need a o2 sensor put into the b-pipe.. it will cost you about 15.00 to have that done.
also the a'pexi is a lot cheaper than the greddy and its b-pipe is powdercoated too..

 

Who sells Apexi? I priced a Greddy catback at 539.00 no labor. With my 97, will I need to deal with the sensor too in the B pipe area?

 

you will need to have your sensor installed. any muffler shop can do this cheap..
i have seen the a'pexi go for 375.00 to 425.00 shipped.

 

I ended up paying $520 installed. It looks good and sounds nice. Minor adjustment were made, I removed the tow hook and adjusted the tip cuz I did'nt like that it was too "in" under the bumper. I had it cut and then re-welded so that it was "flush" with the bumper. I'm not sure but I think they gave me a 98 instead of a 99. apexi-usa.com
Good luck
Manny