Your VR4 heavily modded?
Have not use NGK7 before but have tried Denso Iridium IK22 which is about NGK7 heat range. To me not much difference since my VR4 is standard stock engine. Currently using back NGK6 heat range only....
I would like to ask something about o2 sensor. Currently my car was doing bolt-on turbo and everything is fine except Engine Check Light on. Once the CE light on, TRC and VSC system disable which I...