I recently replaced the alternator on a LR2, had to pull the intake manifold. I got new gaskets and cleaned the head.
Now when I start it sputters and dies at idle. Almost like it has a vacuum leak. Is there a way to check this or check what sensor might not be reading right?
Any help is appreciated

 

If there is a check engine light the computer will tell you.

 

It isn't 100%, but you can try spraying carb cleaner around the intake seal areas while someone else tries to start it.