Can a cracked exhaust manifold be detected w/Cipher?

[DawgBone]

So I've had Cipher for a few months now and am still learning about some of the parameters and how to interpret what's going on with the truck (haven't had this much fun since I got my first 3-wheeler!!).

Over the past week or so I've noticed a popping/clicking noise coming from under the truck at 3000rpms and above when I have the passenger windows down, and especially before the truck has fully warmed up. I took it to the shop where I got my exhaust work done, and they confirmed that there are no leaks in any of the welds from the y-pipe back. I just haven't had time to take it to the dealer yet.

So after reading about manifolds cracking with some C.T. users I went back and looked at my last 0-60 run that I logged with Cipher and the A/F ratio on bank #2 is a good bit richer than bank #1 at certain points. For example, at 5300 RPMs and 41MPH bank 1 registered 12.64, and bank 2 registered 11.30. The numbers aren't consistently off or anything, but if you look at the graphs, you can tell that #2 is richer over the course of the run.

My question for those more knowledgeable than me is this: IF I do have a crack in the right side exhaust manifold could that leak be significant enough to be detected like I'm describing in Cipher? If so, would it read as rich or would it be lean?

Thanks!

[shailey]

Having a difference in banks is very typical due to distribution of a/f. Here is a picture of one of my consult tickets. Notice the 2 a/f banks? My bank 2 was richer.

http://img2.putfile.com/main/8/22416492982.jpg

The a/f ratio sensors are extremely sensitive, but may not pick up all cracks due to the location of the crack and/or airflow. I have seen a crack that you could put a penny in not throw a check engine light while leak that is smaller than a pin hole will cause the SES light to go out.

If their is a ticking noise that is more prominent at higher rpm, more than likely there is an exhaust leak somewhere and the manifold is where I would start since the exhaust shop has gone over your exhaust system.

Now then, yes Cipher could pick something like this up, but only if you know what you are looking for and even then...it could slip by a computer. A tech putting his eyes and a piece of paper on it would be your best bet right now.

[DawgBone]

Good stuff, shailey - thanks!