VAFC 2 throws a check engine for Vtech malfunction, setting were basically stock, all i did was drop it to 5800. Was going to get tune after new clutch so didn't mess with it much.
Last time it threw the code the RPMS would just sit there right around 6-7K and felt like fuel was cut, had some backfire.
I changed the vtech engagement back to stock and cleared code and car runs fine, but now I'm worried about getting a tune with it if this will happen after and money is wasted.
Any help would be helpful.

 

I used the vafc 2 on my 97 supercharged civic and it always set a check engine light for vtec. But only if I hit vtec before the engine got to normal operating temp. The factory ecu has a safety on the 99-00 b16 si that wouldn't allow vtec to engage until the car was at operating temp. The vafc bypasses that safety. Which COULD be why your setting a vtec code. If the ECU sees the vtec pressure switch engaged below X temp it sees a fault and sets the code. Now not 100% sure if it works the same way on the S2000 but it's highly likely.

 

What code

 

Its definitely not a temp thing, both times were after the car was fully warm.

I didn't write down the actual code, Ill try to see if I can still get it.

 

make sure the vtec oil wire is wired correctly. if not itll throw you off of vtec then ull have to disconnect negative on battery for it to reset

 

Yep, Im going to go back to the wiring. Id like to get that all set so I can go and get it tuned.

 

was that it???

 

Nope, checked the wiring, it was all good. Threw the code again, vtech was set to 5900, forgot to check the exact code again though. Set it to 6100, had a full day of autox and no codes with that setting, anytime its set to below 6100 it eventually throws the code and feels like a fuel cut.

 

You should not get a check light with a correctly installed vafc2, your wiring is wrong or something there are a few prerequisites for vtec engagement.

 

Well it engages, but after a while off being in vtech the light goes off.