I just had my ECU chipped to have the VTEC kick in at 4800 RPMs. When I reach this, the VTEC does kick in, but the check engine light goes on. However, when I turn the car off and start it again, the check engine light is gone.
When my VTEC kicks in, it seems like there is a loss of power. It sounds loud but the car instantly stops accelerating as quickly as it did before the VTEC kicked in. Could the problem be a bad VTEC solenoid?? If it is all in my head and the VTEC is fine, what is the check engine light for??

 

What car? What engine? What mods? I would guess the cross over is set way too low, but it's hard to tell without additional information related to your car.

 

Sorry
93 Civic EX
1.6L VTEC
Intake, Exhaust, Header, Hotwires

 

i just checked it it's code 21, which is the vtec solenoid spool now what do i do???

 

I would pull the solenoid off first and check and make sure the filter is clogged.

 

knock senor