so i swapped out my y7 intake manifold for the y8 and when i turn the car on it revs up to 2k then goes down to 1.5 and idles there. when i push the gas it goes up then back down to 1 and sounds like its gonna die but doesn't then idles back to 1.5 and while i was driving it when i go to slow down and put it in neutral it will go up and down from 1 to 1.5 like three times then idles back at 1.5 whats going on?
