ok i got a catback and cold air intake installed now everytime i drive at high rpm around 5,000+ the exhaust feels something is stuck inside it and is trying to push it out it happens (makes a popping sound for a few second then normal again) in first and second gear, the car starts jerking if i don't push the gas down hard enough, car idle is kind of rough and CEL , oh yeah there this ridiculously loud whistle noise i checked the intake no leak or anything but the noise is comming out the intake air filter, help please

 

Which CAI did you get?

 

custom made one bought it for $560 Au

 

I'm sorry to say this, but we've seen many custom CAI be the cause of issues.
If the ID or the length of the tube isn't correct, or if screens aren't installed before the MAF, it cause problems with your MAF readings.
If this custom intake removed the VFAD and you didn't cap the fitting behind the throttle body, you'll introduce a vacuum leak.

If you switch back to the stock intake and everything works... you know what the issue was.