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Sw. Exhaust Insert For Pulling Cat Converter ?

By morganism, March 5, 2016



Anyone doing this ?

I hav folks car in rural area, no emmissions, 2001.

I understand these clog up regularly, would like to just not keep replacing...

Shouldn't be clogging up unless something massive is flowing downstream - like in the case of heavy oil consumption / poorly running engine. Even then, there is a significant amount of free space around the catalytic block material - even cars guzzling a quart of oil every couple of hundreds of miles will not clog a cat converter.

As for pulling the converter - since the 8th gen's OEM setup has the cat, resonator, and mid pipe all as a single component - you'd have to cut off the cat and either weld on flanges to insert a test pipe or just weld in a straight section of piping.

Unfortunately, this means that you'll have to do the cutting and welding yourself - as a shop cannot "legally" remove pollution control equipment from a vehicle, even in areas without required emissions.

Can opt to replace everything from the front pipe to the exhaust - just have the shop spec out an aftermarket cat that has flanges on both ends - then you can go home, unbolt the exhaust and insert a test pipe.

Of course - all this doesn't solve the issue of the downstream O2 sensor (post-cat O2 sensor). You'll have to wiring in a O2 simulator or build your own box. If not, you'll have that CEL light on the whole time. I'd suggest not taping over it with some electrical tape, as you could get a valid CEL for something completely else / need to see if the CEL flashes in cases of severe issues.

I understood the 2nd/downstream O2 was added later, after vehicle spec. Does it throw enough info to knock computer out of the loop ?

I figured i would have to cut and paste the exhaust myself, unless i can find someone who makes one aftermarket...

My Land Cruiser ate the cat, it blew the chunks into the muffler, plugging the muffler.

Am assuming this is possible here also.

Have found a replace muffler on Rock Auto, and a full replace from exhaust header back for 300........

Hmm,

Is the resonator flanged ?

If the cat plugged that, I should be able to just replace the muffler, and leave the cat alone.....

Downstream O2 sensor is there mainly for verify catalytic converter efficiency - doesn't really add into the air/fuel mix needed for operation. But I've heard it does influence long term fuel trims. Shouldn't cause the car to run in open-loop mode though.

Nope - the resonator is welded inline with the rest of that part. Atleast on my 2002 - that part runs from the front pipe (that short section that runs from the exhaust manifold to the cat - front O2 sensor is on this part) - to the flanged exhuast pipe that runs to the muffler assembly. About 6 feet total length - short section of pipe that slips in the front pipe, then cat, then resonator, then midpipe, to a flange.

Might be able to piece one together from aftermarket parts - as most have the catalytic converter separate. Can always get a shop to cut off the cat, weld on flanges and put on an aftermarket cat. You can then bolt it for testing purposes - see if does anything different.

Short term testing - you can pull the exhaust from the front pipe back. Will be crazy loud and you'd get exhaust gases in the cabin of the car - but that would definitely tell you if the cat, resonator, or muffler were the issues.

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