Rock Auto 'Ultra-Power' catalytic convertor

Somewhere on my build thread theres the "pre-cat saga" - cut a long story short I went through about 3 or 4 rock auto brands for the pre-cats and they all seemed to come from the same factory, unfortunately that meant that the header connections on all fo them were crooked and thusly none of them fit up to the exhaust manifold even closely.

I wound up with Magnaflow 49 state legal "hi flows" - they're great, stainless and fit up wonderfully, haven't given me a lick of trouble since. That being said, I don't remember them being the 1K I see on Magnaflows site - closer to like 4-600 IIRC.

It is worth noting that the the actually Catalytic converter part on the Rock Auto buy's all looked great - nice consistent honey comb and solid, I wouldn't hesitate to use one of there main cat's and the pre-cats probably work great if you can get the damned pipes to fit up.
 
Alright, It's in. Sorry, I forgot to get pics.
When I opened it, it looked like the cats were at the wrong angle to fit properly. Maybe that was because the two into one happens in the middle of the oil pan, as opposed to underneath the Cats.

The flange clamps were robust, probably 3/8 inch. The welds were about what you would expect for $200 Chinesium.
I had an exhaust shop do the install as I needed to replace the muffler and redo the tailpipe to get around my new Genright 24 gal. Safari tank.

Muffler guy said it was a straight forward install, no drama. I had him install a 'stockish' quiet muffler. It sounds great. I'm quite pleased.

As an aside, lately I had been experiencing an erratic idle, not wanting to come back to idle, like I had a vacuum leak.
That is gone. I never got any Cat related codes, but maybe my cats were bad. (150K miles}

As another aside, I don't think my rear main was leaking. It looked fine when I removed it, and the leak is still just as bad.
I'm thinking valve cover gasket. Ugh.

But long story short, I would recommend this Cat.
 
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Rear main recently replaced? There are rear mains that will eventually leak and those that are leaking.

Yeah, replacing the rear main was how I messed up the cat. Not sure what I did wrong, because I did the the same job several years ago when I got it and the cat and seal both worked fine afterwards.
 
Yeah, replacing the rear main was how I messed up the cat. Not sure what I did wrong, because I did the the same job several years ago when I got it and the cat and seal both worked fine afterwards.

You probably didn't mess anything up... unless you slammed it around a bunch. It was already going...

Silicone lubricants can poison catalytic converters.

-Mac
 
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If it had an exhaust leak after being reinstalled, it could have killed the precat by running that bank too rich. You may want to discharge the PCM to force it back into learning mode if not done previously.
 
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