The engine light came on no noise what can it be? I was told the manifold

He just said that the part that opens and closes for the airflow I believe is round inside keeps getting stuck in the open position. He also said that the manifold for those first jeep compass where faulty so jeep came up with a replacement and the whole manifold needed replacement. He wants $750.00 to fix it.

Doesn't sound to far-fetched to me. Do you know and trust this shop/mechanic? Only other suggestion I would have is to ask for a WRITTEN guarantee of diagnosis AND repair , before authorizing work. MY point being , can he guarantee there are no other underlying issues (probably unreasonable to expect) , if so , HE has seen your vehicle , whereas , I have not, IF he believes there may be more than just this one issue (but this IS the major one that must be done first) , then he should let you know that up-front (that would be reasonable). I hope this made sense. Good luck.