Its the throttle body.
I had the same issue and replaced mine and it works properly now.
Here is what mine sounded like
https://share.icloud.com/photos/08Nvf2-QArQS8tGvYWvu7yzqQ#Home
He tuned my car with the 18 manifold and LU47 injectors.
The car is perfect first tune he sent was on the money and after dataloging he said it was great as well.
He always answered any questions ive had in a timely manner as well.
My car is a 2016 GT PREMIUM non PP car
I have the 401A nav package with shaker pro.
The oil pressure gauge did not work at all untill i had Lund update the tune on my car.
Of note i was not on a factory tune at the time of install. As i had previously installed the 2018 intake and Lu47...
That is not correct as has been mentioned several Times in this post and others
A 2016 GT premium non PP car does require a tune to activate the oil pressure switch.
This is on a 401A manual car.
Nothing else is required other than the tune update to enable the sensor.
The wiring harness is...
The port in the back should be blocked off as well as whats called vaccuum 1
This runs straight through the manifold to feed the Imrc valves which in this case are not being used.
I simply capped both ends off and have no issues with using the lockouts.
My car is tuned by Alex F at Lund as well and he has done a great job on my tune and always gets them back in a timely fashion and answers any questions i have had. I previously had Dakota and he was spot on also.
I have no complaints about Lund.
After first trying the plug and play route and it not working.
I then hardwired them inplace and it still did not work.
So i locked them out and didnt look back.
I got tired of pulling the intake and redoing wiring connections its just not worth the hassle.
On A 2016 Gt premium non performance pack the wiring for the gauges is already in place. Its behind the radio look for a small square hole and you should see one or two pins through the hole. Simply push this pin backwards untill its comes loose and then fish it up into place. This is a factory...
Has any one noticed their exhaust note change.
By that i mean i have the magnaflows on mine and the sound or loudness has been drastically cut volumewise.
I would have never thought that would happen.
The rumble i used to get when id let off the gas while coming to a stop at is almost gone...