I have another question

[Rex012]

So I went out changed the calibration to try to solve the low power issues. Also checked the injectors cac and any leaks and I found none. What I found what the turbo starting to fail but it's still about the same power even after changing the turbo. It seems like the boost is cut back after you shift once. Also the engines sound is much lower compared to another isx. The truck feels weak and The fuel rail pressure is around 280 psi and there are no check engine lights or stored codes. What else should I check ? The regen history is great something like 1.8 on all regens. Any help on where I should look ????