For those with MAC headers and exhaust leak problems, you may want to read this.

Well, just look at the picture below.

Header Leak Picture

No wonder the headers still leaked when I changed header gaskets. The #7 primary was leaking at the inside weld at the collector!!! This is the drivers side. I couldn't believe it. All that work to change header gaksets and it turns out to be the header collector weld.

I couldn't see it until I had the header off.

I looked at the rest of the exhaust system connections and there were absolutely no leaks anywhere else, including the header gasket in this header. (the drivers side) The Mr. Gasket Ultraseal gaskets work great with Permatex Ultra Copper RTV on them. There were no leaks at all there. The primary slip tube wasn't leaking at all either.

Well, off to the exhaust shop soon for a quick weld. I'm actually happy now because I know that I have the problem solved.

Oh yeah, the leak is right in front of the O2 sensor.

Dan

 

I'd really consider shipping that back for an exchange...

 

Yeah, I thought about it, but with the backorder of MAC mids at Jet-hot, I doubt I would be getting a replacement anytime soon.

It's really not that big of a deal. I'll have it welded, and that's pretty easy.

The only downside was the time finding it, and that I scratched up a few of the header primary surfaces getting them back off the car. I have some silver 1200 degree header paint that I'm going to touch it up with though. You can't see where the finish got scratched when the headers are in the car, I just want to prevent any rust. I'm not sure if I even scratched thru the coating. I just rubbed it pretty good in a few spots.


I knew that something wasn't right with this exhaust leak. I couldn't believe that the headers were still leaking after I put those gaskets on with RTV. Now I know why.

My PCM is out for reprogramming (Ion at www.madz28.com) and I should have the headers bolted back up just in time for the PCM to get back. Early next week I'll let er rip.

Dan