Help with exhaust manifold for 93 corolla

i have a base model 93 corolla i need to put in a new exhaust manifold but im stumped over the two types. you can buy 1 is a basic one and other has this O2 sensor provision or whatever. i took a pic of the car and it seems the o2 sensor is on the pipe after the manifold itself so im thinking i need a basic theres a pic .

another question i had is the old bolts attaching the front plate of manifold look very rusted, i would like to replace these with new, what size bolts are those and what type. i read somewhere people recommend you put something like “never-seize” on the bolt before tightening them. any help will be greatly appreciated. thanks alot.

It sounds like you’re kinda new to this, don’t get me wrong, I’m not being critical. Exhaust manifold stuff is really easy to break, you may need heat (a torch) lots of penetrating fluid, patience, experience, and maybe this one is for a shop. On the other hand, if you’re going to try it, get a picture of the new part(s) and try to match it up with your actual. It sounds like your 02 is “downstream” from the manifold which makes this an easy one. Anti-seize never worked for me on exhaust stuff, just my experience. Good luck! Rocketman

The heat shield bolts might come out easily. But if they break off who cares?

You’re replacing the exhaust manifold anyways. So the broken bolts will be tossed out with the old manifold.

That’s a 10mm hex head bolt. So the thread size is most likely 6mm X 1.25 X 14mm long.


@Tester is right about the heat shield bolts. If you break every one…it doesn’t matter.

On the other hand the bolts that attach the exhaust manifold to the engine head may be another story. These can be pretty dicey to remove after 20 years of being untouched. Remove the heat shield first, then take the car for a good run to bring it to operating temp. Then try your best to coat every manifold bolt and nut with penetrating oil and let it soak in for a day. The warm engine will allow the oil to flow a little better.
Have patience with those bolts, because if you break one off at the head…you may need to remove the head to have access to drilling them out.
Once those bolts are out replace them with new ones. Just take them to the auto parts store and they can line you up with new bolts.

If you only have a minor crack in the manifold and it is a little noisy until it warms up…I’d leave well enough alone.


The nuts that hold the manifold to the block can be a challenge. Use a wire wheel to remove as much rust off the exposed threads as possible. Then soak them with a penatrating oil. Use a impact gun and a good 6 point socket and they should come off. If they are really rusty you can heat the nuts up with a torch before removing them. Don’t reuse the nuts,