Is it worth it to put an intercooler on a 2000 SSEi, or would a cold air intake, with a box (like the PIFK kits) be just as good? Has anyone ever installed an intercooler on an SSEi??

They have different jobs. I suggest an Intense racing FWI, after you have that, smaller pulley and other mods you can get an I/C. For the cost of an I/C you can give your car a huge kick in the pants

theres a lot more mods you want to do first be you think of an I/C

X 2. Its not a matter of whether the intercooler would help, its a matter of getting the most bang for your buck. How far do you want to mod your car? A few add-ons for some extra kick, or push the limits?

Read this (if you haven't already):

https://www.gmforum.com/t278662/

You can add a IC at any time and it will help. Will you get the full benefit from it right away? No. You will need to open the exhaust up to allow the engine to breath. Headers, free flow cat, rockers or a cam. Without that the engine will take in more then goes out. Take that roughly grand the IC will cost and put it into your exhaust.

X2...The IC true benefit will be realized when your start increasing boost by dropping pulley sizes. The IC helps to keep the air charge cooler which means denser air. Denser air means you can add more fuel. Cooler charge means you can take full advantage of adding timing. More timing increases pressure. More pressure creates heat. More fuel and heat means increased chance of knock retard. Knock retard means damaged engine.

My personal opinion is to buy tuning software like HPtuner first. You will need it.

x10

you can't go very far without having a tuner first

X20 - You won't want to put an intercooler on until you have mastered the tuning. You wont be able to gain thge benefits of the Pro parts without a tuner.