49dream, your topic here in General Truck about the exhaust manifold is still in listed here the forum topics.
When you click on it, there is a new link in the body which will take you to the new location of your post.
As others mentioned above, posts are routinely moved around to a place within the forums that is more likely to cover the information you are seeking.
If you click around the forums list, you will see that we have many, many areas of sub forums covering specific areas of trucks.
Please read this post below, which is all about the posting rules here in General Truck.
Why posts are edited, moved or deleted. Please read before posting.
Welcome to the 'Bolt, we are glad to have you.
-W