Installed the HKS SSQV blow off valve, drove around the neighborhood and everything is fine, did some 3rd gear pulls everything works fine.

However, on uphills, under minimal throttle, aka in 5th gear just cruising the car makes me pull over and says service required.

Code is P1241

Erased codes and restarted car and it works fine everywhere again unless you are cruising on uphills. Double checked hoses and clamps and all that good stuff.

Put the stock back on and tried cruising uphill, no problems.

I know blow off valves didn't work on 8 and 9's but I've seen a lot of people run blow off valves on the 10's.

Also my blow off valve doesn't mount in the stock position, but directly to the Nisei LICP.

Any ideas?

 

I think I found the issue:

"Installed the HKS SSQV blow off valve."

 

this is even better:
" I know blow off valves didn't work on 8 and 9's but I've seen a lot of people run blow off valves on the 10's."

 

There's your problem right there. "Installed the HKS SSQV blow off valve."

 

Since the stock BOV is working perfectly, why change it? The stock one will hold plenty of boost and won't have the negative effects on drivability.

 

This.

+1 with all others. Not a good DV for the Evo, in any platform.