OK I am not sure if this is related but I have to replace the exhaust manifold on the passenger side for the second time this year. The first time in the spring before the noise started I replaced the manifold and gaskets because of noise. No after my last trip the noise is back and it turns out the new manifold is warped so I have to change it again. Could this be related with the other problem?
For the exhaust manifold problem, you’ll have to get the ECM diagnostic codes read. That’s the place to start. A air/fuel mixture or cat efficiency problem could cause that for example, and would likely post a diagnostic code.
Hello! May I ask what was to final solution to your problem? It seems like I’m on the same boat now with my 2006 F150. I’d really appreciate your disclosure on this. Thank you.
If no reply from OP, which is likely given that’s it’s been 7 years, suggest to post your problem as a new topic. You may get some good ideas here. Click maintenance/repairs upper left, then new topic upper right.
Still I think if you read the posts from sarge, mustangman, and Nevada, that’s about the best you will get.
Keep us informed what you find out @Frank10 . It seems like the first step is figuring out a way to prevent the hubs from switching modes, experiment to see if that effects the noise. I believe there was a thread on a similar topic here not too long ago as well. You might be able to find it using the forum search feature.