B serious

No, the valet key doesn't slow the car down to 25mph and give it no power. It just doesn't allow the trunk or glove box to be unlocked.

OP. Is there a check engine light on? Does the check engine light work?

Why not just have it inspected. There are about a billion reasons why this could be happening. Nobody on here is going to be able to give you an answer with the question you've asked.

Boosted04S2K

Just to verify, did you drive it before you changed the tensioner? One thing to check for that can limit the engine that much would be a blocked exhaust system. Where did you get it? Did it sit for long?

noodels

Brakes seized on !!

Alexs '05

What area of Miami? Have some friends down there who are very knowledgeable with their S2000's and can probably point you in the right direction to figure this out if you haven't already.

soulicious

Just curious, are you using a standalone ECM (like AEM EMS)?

s2000Junky

Sounds like the car has triggered a cel/fault. Some of these will limit the rpms to about 3k depending on what the fault is. You need to read that code and figure out what it is. But resetting the ecu/pulling batt terminal would/should temporarily fix this, until the cel gets triggered again. You need to figure out what the cel is before you possibly cause engine damage if there isn't already.

RolanTHUNDER

What if they push the button inside the middle glove box, wouldn't that still open the trunk (or would that button be rendered unusable by the valet key in the ignition...?)?
Just curious.

OP: reset your ECU and take it from there. If the car sat unused for a long time you should run some fuel system cleaner as well.

Chuck S

Lock the center compartment if you want to keep the valet out of your trunk. The valet key will not open it (or the trunk). I never got this key with my used car. But don't let valets drive it anyway.

-- Chuck

RolanTHUNDER

Yeah that's what I figured. Lock the cubby to prevent access to the button inside. No valets allowed to drive my car and I do have the valet key, full 3 key set in fact with my '00