Questions from Encik Razak Moss from YouTube:

If I had changed the Myvi Gen 3 4-1 Myvi Max Racing Exhaust header of yours, but noticed that the fuel consumption is quite high compared to when I used stock. But my exhaust system is still standard. What would you recommend to me.

(This question is translated)

Solution:
@razak moss
It sounds like you skipped the step that is designed in our upgrade system.
To avoid unwanted issues , it’s advice to be stage 1 > 2 > 3 > 3+
Any skip of stage will cause unbalanced output and fuel consumption like you’re facing now.
Best advice is, you’ll need the exact full system (including the intake system) to get the best performance and fuel efficiency.
Our tested results for fuel consumption is almost similar to stock with the full stage 3 plus system.
More about this upgrade details for Perodua Myvi Gen 3 upgrade is available in https://maxracing.co/mg3