Hi,

As a result of a recent coolant leak on the driver's side head, I believe I have a partially clogged catalytic converter on that side (I have 97 - dual cat setup).

I believe this is resulting in blown out header-to-collector gaskets - no matter what I do to seal it up.

Is there a dedicated exhaust backpressure tester out there that I can buy or can I just use a vacuum tester or a compression tester and attach it to the air pump inlet on the top of the header?

I would think the range on the cylinder compression tester is not precise enough for the pressures I will be seeing in the header.

Also, if the backpressure is high, as I suspect, has anyone just welded a new stainless catalytic converter into the stock driver's side Y-pipe or do I have to go and get a whole new Y-pipe (one that would replace the driver and passenger side Y-pipes - they are separate pieces on the stock 97).

Also, what stainless alloy are the stock Y-pipes made of - just to make sure the new cat will be compatible for welding.

Naturally, given the cost of a whole new "catted" Y-pipe, I would rather just weld in a new cat on the driver's side Y-pipe.

Thanks, gents.

 

One other thing I have heard is that there is a way to clean the guts of the cat to remove the residual gunk that has been deposited to return it's flow and emissions performance back to the level it was before the coolant leak.

Has anyone done this and what liquid did you use to clean it?

The Y-pipe (with the cat) has to come off anyway to fix the fricken header flange leak so I can fill the cat with whatever will work to dissolve the coolant residue.

Thanks.