Passing emissions without pre-cat?

[illusive562]

For what I heard, California 90-91 3sfe Camry's came with a pre-cat right under the exhaust manifold with an extra o2 sensor...Would I pass smog if I removed it and just keep the main cat...?

The reason is that I am getting an exhaust manifold from another state ported and polished, my machinist told me that the manifold might have different bolts California vs Federal (No Pre-cat)...Can anyone clarify this?

I was thinking of getting rid of my pre-cat and purchase a downpipe from a camry before 1990 that didnt have a precat and probrably an ECU...But my main concern is would I pass emissions...

[toyotacamry1]

In california?....good luck.
They won't be happy till they have a duck stuffed up your tailpipe for a natural filter.

[atobe]

^^^ Lol

[terrastrife]

the head dsigned was changed a few times in the 3sfe/ge family, making the exhasut ports line up totally different in later versions. better hope its just the bolt pattern, and not the port size, shape and spacing.

[white90dx]

You have it the wrong way around...

The cat just under the manifold at the front of the motor is the MAIN cat - the same one that is on the federal spec cars. Just under the cat there is a second O2 sensor to make sure that the cat is working. Behind/below the motor is a second cat to help clean things up some more.

With an old motor, the main cat would be important to keep to pass emissions if you could even find a place to pass you without a visual inspection.

Get ready to swap it out to stock every 2 years... If you use anti-seize on all the nuts/bolts when you put it together, it isn't hard at all.

-Charlie

[illusive562]

Originally Posted by white90dx

You have it the wrong way around...

The cat just under the manifold at the front of the motor is the MAIN cat - the same one that is on the federal spec cars. Just under the cat there is a second O2 sensor to make sure that the cat is working. Behind/below the motor is a second cat to help clean things up some more.

With an old motor, the main cat would be important to keep to pass emissions if you could even find a place to pass you without a visual inspection.

Get ready to swap it out to stock every 2 years... If you use anti-seize on all the nuts/bolts when you put it together, it isn't hard at all.

-Charlie

Don't mean to be stupid...so no matter what gen 2 year, all of them have two cats? its just that the 90-91 have an extra o2 sensor...i hope the federal exhaust manifold would fit in mines once i get it...thanks

[JetspeedCamry]

Originally Posted by illusive562

Don't mean to be stupid...so no matter what gen 2 year, all of them have two cats? its just that the 90-91 have an extra o2 sensor...i hope the federal exhaust manifold would fit in mines once i get it...thanks

I think its for Cali car's only. All 3SFE/GE's here have 1 o2 sensor and 1 cat, which is located under the floorpan.

[illusive562]

im pretty confused lol...my freind has an 88 camry but has 1 o2 which is also in california...but i wonder if his cat is under his manifold or under the floorpan like you said...

[white90dx]

Originally Posted by JetspeedCamry

I think its for Cali car's only. All 3SFE/GE's here have 1 o2 sensor and 1 cat, which is located under the floorpan.

All US 3s-fe's have the cat in front of the motor attached to the manifold. Later CA cars (89 or 90 and after) have a sub-cat below/behind the motor and a second O2 sensor. They also have an extra temp sensor to verify that the EGR system is working. Both my '90 CA 3s-fe's were this way.

-Charlie

[white90dx]

Originally Posted by illusive562

im pretty confused lol...my freind has an 88 camry but has 1 o2 which is also in california...but i wonder if his cat is under his manifold or under the floorpan like you said...

Early CA cars were just like Federal Spec cars... This changed in 89 or 90 when a few things were added to CA cars.

-Charlie