90Gt squeal/chirp when hot

[AeroCoupe]

No reason to replace intake gaskets unless they leak. You can start the motor and spray carb cleaner down the intake where it mates to the heads and if the RPM's pick up then you know you have a leak.

 

[General karthief]

The vacuum at the oil fill cap says to the intake gaskets but I'm not there soooooo

 

[Bvoss59]

The vacuum at the oil fill cap says to the intake gaskets but I'm not there soooooo

I ran a code test today and it has a 41 and 91 code. Lean condition, I definitely have a vacuum leak just need to track it down. I’m about to head to the store for carb cleaner to see if I can track it down. I have an upper intake gasket I’m going to replace while I do the valve cover gaskets do you think that the lower intake gasket is bad causing the vacuum at the oil fill cap

 

[General karthief]

Yes could be.