kevine001

I have a 97 LS400. It's got an exhaust leak on the passenger side, by the exhaust manifold. I picked up a used exhaust manifold from a friend who is giving me an entire motor that's sitting on a stand, and I picked up the gaskets for the heads and cat. Did not see any reason to get the gasket for the EGR. Any tips on getting the old exhaust manifold off the passenger side?

Also, looking at the gaskets, my money is on the catalytic converter gasket being bad. Would it be easier/smarter to remove the cat first, and just check that gasket? versus trying to remove entire exhaust manifold??

Thanks.

timmy0tool

iTrader: (7)

I would just isolate and fix the leak rather than remove the entire manifold.
it's unlikely the manifold is bad, though still possible.

have you found the leak?
if you must remove the manifold (or any exhaust hardware) I find that soaking the parts with PB blaster and letting it sit for 10-15mins helps a ton with loosening!

kevine001

Thanks. I'm thinking of trying to get the cat gasket out first. it's a rubber gasket and likely the weak point. if it's intact, then i'll remove the manifold. i'm gonna pull the car into the garage this week, remove front tire and parts on top (air intake, etc.) so i can hit all the nuts with pb blaster. gonna hit them every day for a few days. not working on it until Sunday so it'll have a few days of penetrating oil. i know...overkill.

thank you.

kevine001

Also, anyone know the torque specs on the exhaust manifold nuts? Thank you.

Fit1too

That is an excellent plan with the PB Blaster. Shops don't have the luxury of time to soak things and wait. I can make all the difference!

marvin5881

Check out this video before you go with pb blaster, maybe consider something else.

Fit1too

Very interesting. Thanks for posting the study.