Question About My Is250?

[Vietboy1st]

Hi, i just installed the Takeda short ramp intake in my lexus is250. The car i bought used from none lexus dealer.

The problem i have is when i step on the gas for the car to speed it. the RPM deometer tend to stall at 6 or 7 a 2 or 3 seconds before it changes to the next gear on automatic. Do you guys know why? Does that mean i need to replace a new exhaust system for it to push out more air?

MY plan for the next upgrade is a new exhaust by hks highpower and the rear bumper lips and tint the front windows and windshield to the same color as in the back.

Maybe plan : will wait for the head lamp die out, i will put the led light of lexus 11 or 12 is250 on mine. Or wrap the car in matte black color.

so let me know what is the problem?

Thank you very much