well my bro just got a GSr teg and now the engine light is on for some reason and
when he goes up to vtec and right at 5000rpm it boggs.
what could it be is it a sensor?
we just installed a cold air and he drove it for a day or two and then light came on.

 

jump the engine service connectors(2P) so you can find what's the CEL code is.

 

What he said. When the check light is on, the motor won't go into the fun stuff. No VTEC, no big runners in the manifold. See what code the computer tells you, and fix what it says. What brand/type CAI is it? It should not set a code by itself. It could be just coincidence that it just came on, or something with the install, the parts themselves, or something that happened when installing it. Wire or hose knocked off or something that came off after the install. The code is the place to start.

 

hows that again as i have never did it befor
car need to be on or just befor start postion

 

Do a search for check engine light or cel codes or something similar. https://honda-tech.com/zerothread?id=526516 This one has the basic procedure. Find the correct connector on the side near the glove compartment, short the connector, and read the codes the cel flashes. Then either look it up in a manual or do a search for the code it reads. Whatever the code is for will be why the cel light went on. At this point I would strongly urge you to find a shop manual for the car. It will cover all this stuff and make your life much easier.