1993 3.2l SHO badly failed emissions.

[Ksoder]

Is there a chance of it fixing all three

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[SHOMON]

The numbers were so close that I bet filling the tank with some fresh premium fuel, and taking a nice spirited highway drive might just do the trick. That will at least clear out all the carbon built up.

 

[Ksoder]

The numbers were so close that I bet filling the tank with some fresh premium fuel, and taking a nice spirited highway drive might just do the trick. That will at least clear out all the carbon built up.

The problem is that the car doesnt have any plates so I cant really drive it anywhere other than to the emissions place

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[SHOMON]

The problem is that the car doesnt have any plates so I cant really drive it anywhere other than to the emissions place

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Ah crap. That sux. Sometimes they just need to be driven after a tune up to get the fuel tables and such back to normal. But with the spout pulled and it not getting unmetered air it would not surprise me that it passes.

 

[Ksoder]

Alright im getting it tested again, just filled it up with premium so well see... I drove it here in first and second gear only so its warmed up

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[Ksoder]

Well, after fixing the air leak, my emissions went back up...

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[luigisho]

Holy crap. What are the numbers. This is crazy.

 

[Ksoder]

Holy crap. What are the numbers. This is crazy.

New cats are on their way

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[Ksoder]

What do y'all make of these numbers?

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[rubydist]

was working all day so just saw this.

pulling the spout connector usually drops them around 50% so your experience there is in line with what others have seen.

you need to drive it for 20 minutes before you go to the emissions place - you need the cats fully warmed up and also you need some time for the fuel trims to get back in line after you fixed the vacuum leak. find a way to do that on the back roads or whatever so you get the pcm dialed in before you go back.

there is some stuff you can buy at the auto parts store that is "guaranteed to pass emissions" stuff that you put in the gas tank. I think with a can of that you will pass now, after you drive it a bit.

 

[sperold]

In one of my desperate attempts, I tried a can of "Guaranteed to Pass" tonic, and it did not pass.

Since you are not already on the road. it is difficult to get the hours and miles it takes to correct things that can be done by daily driving.

Your existing cats could recover some if allowed the time to burn off the months of extra fuel load they have been doing their best to handle, but you don't have the luxury of time to do this.

So maybe the new cats are the quickest solution.
I have heard of people having a new Y-Pipe for E-Testing and then swapping back in the original pipe for the 2 years between tests.

Although I have never heard of it, could an ECU have been damaged by a power surge or some equivalent.
Your issues seem so fundamental, that it looks like a computer issue, to the uniformed, like me.
It would have been nice to swap in another to test that theory, but that is a tall order.

That ECU tune up you mentioned before still haunts me. Maybe a previous owner had used an external chip that messed up the internals, and removing it only restored it to a point.

The new cats should get you across the line, but there are differences in cats, as some have more precious metals than others, and performance cats seem to have the least.

 

[luigisho]

That ECU tune up you mentioned before still haunts me. Maybe a previous owner had used an external chip that messed up the internals, and removing it only restored it to a point.

That's been rattling around in my head too. That, injector leak, cats, dpfe. What a PITA trying to get at this while the car is an easy ticket target without the pass. Old SHO ownership needs a backup vehicle.

Mine has been sitting idle for a month with an airbag issue that I don't have time to chase & state insp. also expired last month.

 

[Ksoder]

Im about to pull the section of exhaust with the two cats out of the car, any tips?

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[sperold]

Soak your exhaust manifold studs with liquid wrench or PB Blaster for a few days in advance. Get some up on top of the stud as well, as the stud goes through the exhaust manifold (open hole up on top).

Breaking one of those studs is the start of a long process of drilling out the old stud.

If you know a good exhaust shop with competent people, consider having them take the nuts off the studs, there are procedures and tricks only they know. They may run a die over the threads that are showing, to help the effort. They have been known to get the old exhaust studs out by heating and cooling the manifold itself.

 

[SHOCH]

I'm a huge fan of 1/2 trans fluid and 1/2 Acetone mix, found it waaaaay better than PB Blaster or anything else.

 

[luigisho]

Are you cutting and splicing replacement units into the original y-pipe? Get a replacement graphite donut gasket if your's is old and beat up. Helps seal the y-pipe to cat back exhaust sections. Should be a couple bucks at any auto parts store.

 

[Ksoder]

The whole assembly from where it bolts to the manifold to the y pipe is out, not even any problem bolts... The one I ordered is a complete unit so no welding or cutting just bolt in

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[luigisho]

Which unit did you buy? Hold on to the old unit in case it was not the problem. You could always have a backup or sell for platinum. If the new unit does not come with a new gasket you will still need to get one from the store.

 

[Ksoder]

Davico 55560

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[luigisho]

Interesting. Never heard of them. Report back with fit and finish. That price is good.

I already have an idea about the cats given the price point and 49 state declaration. I hope it gets you over the finish line.