Okay so Im getting a CEL 21, not a gas tank CEL as i suspected.
The CEL ONLY comes on after the car has been idling for a while, long after it's in operating temp. When CEL is on i can only rev to 6500rpm in a snails pace, its not engaging VTEC.
What could be the specific issue here? Remember the CEL only shows and stay on after it has been idling for a while, long after it’s in operating tempature.

 

Code 21 means the is an issue with the wiring to or with the actual VTEC solenoid. However, it is diagnosed during the initial ECU power-up sequence and should show immediately and not after a while.

Although cleaning it shouldn't really help since there is an additional sensor for VTEC oil pressure, remove the solenoid and make sure the metal filter has no debris. Another option is to borrow a solenoid and test it to see if the problem goes away before buying a new one.

Good luck!

 

Okay thanks, will try cleaning it and see if i find anything. It's a weird issue, the car is functioning perfect (rev fully, with vtec), and you can go for rides without it appearing. However when the CEL shows it limits to 6500rpm in 2nd gear, revs slowly with no vtec.

 

Update from my previous post, regarding CEL 21. It only does this when the motor is at operating temp, and has been parked for 5 min or been idling for a while. After which the CEL light comes on, and the rpm's are limited to 6500 in 2nd gear (not engaging VTEC)
I measured the VTEC SOLENOID, and it shows 14.2 ohms. I've read it should be around 14 to 30 ohms right?
Could this be the cause of the issue?