Hondata

I am building a LS/Vtec (B18c1/B18b1).
I have a p72 ecu.
Do I need to install the knock sensor or can I just use the disable function in the s300 software, to use Vtec?

Thanks

Exactly as the title says when I start the car it goes up to like 1700 rpms then it immediately drops down to 1000. I checked the idle temp in the s300 and it is what is supposed to be(the stock settings)

I have a p72 in a 94 ls/vtec with an s300

Any Ideas would be helpful