I broke the O2 sensor bung off the exhaust manifold yesterday trying to get the O2 sensor out (broke without almost any effort), and I'm trying to figure out what to do besides completely replacing the manifold. What is the stock manifold made out of? It looks like it can be welded (I see welds on the pipes...) but I'm not sure. Any idea? Is it cast iron or something else?

Thanks for the help,
Steve

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1987 Fiero - 2.5L, auto tranny, stock
1970 Firebird - built 455+.030, lots 'o mods

stock exhaust manifold is made of stainless steel. Easy to weld with a MIG or TIG.

Thanks! Thats what I was hoping to hear. When I looked at it last night it looked almost like cast iron, but then I noticed it wasnt one big cast this afternoon. I didnt want to bother my friend with using his welder until I knew for sure it'd be weldable.

Thanks again!

To do it right you'll need to use the proper filler metal, likely 410 or 308 stainless, and 100% Argon shielding gas. Generally the easiest way to do this is to use TIG for the repair. Be aware that this manifold also generates lots of cracks in the main body and at the welds to the two side tubes.

JazzMan

don't even bother...

go to almost any salvage yard and get another manifold or three for cheap. The same manifold is used on all the FWD cars with that engine. I've never payed more than about $20 for very good used ones.

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The only thing George Orwell got wrong was the year.

The Ogre's Fiero Cave (It's also at the top of every forum page...)

Even $20 I dont spend on stuff I dont need is $20 I save.

I'm going down to my friend's shop tomorrow to see if I can weld it on with the manifold still on the head. If I have to take off the manifold to do it I'm just going to buy a new one. The main issue here is I dont want to snap bolts off in the head, plus I'd rather save my $20 for the next thing that breaks.

Just an update. I went over to my friends shop and welded the bung back on. Its working nicely now, and having a working O2 sensor helps the drivability a lot!

Thanks to those who contributed, I'd give you a + but I havent been on here for 30 days yet

[This message has been edited by PontiacMan (edited 03-29-2004).]