Can a de-smoged FJ60 2F run a catalytic converter? (1 Viewer)

[psulick3]

I need an assist here. I have a de-smoged (PO did a great job and the 2F runs like a top) '84 FJ60 which I have titled in Virginia. As the vehicle is over 25 years old, no emissions check required however, the safety inspection was recently amended to include a visual check to see if the catalytic converter is there. Mine has none. Obviously this is a big problem. I do NOT want to re-smog my engine. Would it be possible to simply cut out a section of the exhaust and put a cat in without having to alter anything on the engine? I am concerned with back pressure issues or having to re-jet/calibrate the carb. I am aware of the legality issues surrounding my proposition. Just wondering what effect it may have on the system. Thanks in advance.

 

[brian]

so you buy a cat, but unfortunately when it shows all the catalyst falls out of it. due to time constraints you need have the broken cat installed into the system anyway.

 

[micruz60]

Welcome to the mudness.

You can do it, I doubt it will have major effect on the engine performance. You could also straight pipe thru the cat converter, and the visual appearance is the same. If there is no 'sniff' test, then no one will know whether or not it is producing more HC and NO2...
HTH

 

[Output Shaft]

The answer to the thread title is yes. No problem at all. The cat won't overheat and the back pressure won't hurt anything. And people following behind you will benefit.
The carb doesn't care.

Some guys "desmog" but leave the cat installed because of the stench of a non cat engine.

It's reeeeeeeaaly easy to tell if a car has a properly functioning cat installed instead of a hollowed out "fake cat" that looks real. Just start it and take one breath.

The exhaust stinks like holy hell and will stink up the entire area quickly. No joking. The exhaust stench from a cat-less car can be smelled from over a hundred feet away easily by a human nose.

Just pulling up to the inspection area may give you away. Also without a real cat, the exhaust sounds illegal anyway.

Get one of these on this thread:

Another Catalytic Converter Related Question

 

[jlhollowx13]

My desmogged 60 still has stock exhaust with cat, no issues. My 40 is desmogged with no cat, no issues.

 

[psulick3]

Thank you guys so much for the replies. I would like to run the cat for the slight earth-realted benefits but mostly to clean up the smell coming out of the tail pipe. It's a big relief to know all I have to do is stick one on the system with no added fuss. Now on to the leaf spring bushings...

 

[brian]

without an air pump to heat the cat, it's going to do little if anything other than obstruct the exhaust.

 

[Spike Strip]

You can have a cheap universal CAT welded in at any muffler shop (find a good one). It will run fine and even be a little quieter. If you want a nice low-restrictive type, get the universal 49-State Magnaflow.

 

[Output Shaft]

Even without an air pump (smog pump), the exhaust is much, much less stinky than without a cat.

 

[Random Dan]

My truck has factory sans cat exhaust and I've never noticed the exhaust smell unless it's cold and running on choke.

 

[Joe_E]

I have a cat and desmog. Truck runs like a top.
If you have done a proper desmog and still have a good tuned factory carb you should have no issues.
All bets are off with a Weber...

 

[Spock Dingledong]

I certainly hope so. I do and yeah, runs well. that being said, it ran HORRIBLY before the desmog (massive exhaust mani leak, Air Rail broken, smog pump pumping into the bay). So maybe it still runs poorly, just comparatively better.

 

[HemiAlex]

That really depends on the tune. My 6.1 Hemi in an old car doesn't have a cat, but it doesn't smell due to a perfectly tuned EFI system.

 

[psulick3]

Just to circle back if anyone else finds this thread, I found a $50 Flowmaster on Amazon and had it welded in at the local muffler shop for $150 (they had to remove part of the exhaust system to do a professional job). Works great. No issues at all with the desmog and passes VA inspection.

 

[Swampcruiser45]

Do grown men really use the word " stinky exhaust"?

 

[TexasBlue]

How bout just running the exhaust thru a cat than out to the tail pipe, skip the muffler. I believe JimC told me he did this for awhile and the exhaust note was a good sound.

Im still smogged and deleted the cat from my exhaust. It sounds better, $36.00 turbo muffler from Oreillys. Exhaust smell, any carb`d motor probably will have some sort of noticeable fumes over EFI/modern emissions equipped vehicle. Here in TX we don't have rules on rigs over 25 yrs.

In January plan is for full desmog and adding a header. 2F with header, turbo muffler, desmogged and tuned right sounds good, the rv cam woulld be the real plus.


So you have options, it won't sound like a LS1 or vortec, but it kind sound raspy with nice note..

 

[OverLand Cruisers]

How bout just running the exhaust thru a cat than out to the tail pipe, skip the muffler. I believe JimC told me he did this for awhile and the exhaust note was a good sound.

I've done this on a few rigs and it sounded pretty good, similar to a turbo muffler.
Good option for those who need a cat and want some exhaust note.

 

[NeverGiveUpYota]

Reviving.... stink like oil? My rebuilt engine has a City Racer carb and I recently pulled my pan worried something was up. I have an extra and it was a plan at some point anyhow. I have no smoke w/ start up or driving but while driving the truck stinks bad.
I am desmoged and have no cat, that’s the reason?
I will add when I got up high and looked down on the passenger side I noticed my CC solenoid was unplugged but that’s only for shut down correct?

 

[Seth S]

The cat is built with oxidation and reduction beds inside. One needs an oxygen rich environment and one requires a hydrocarbon rich environment. The cat functions properly with an oscillating rich/lean exhaust mixture. So if all of your smog equipment is removed then a carb on its own has very little capability to change the mixture. There will be some rich/lean effect due to throttle fluctuations but not like you would see in the stock form. Modern cars use an O2 sensor as input and are constantly adjusting fuel flow through injection.

So in just sticking a cat on your exhaust it may do a little to help or it may burn out or plug up. It’s just one piece of a system and it won’t work as designed if you remove all of the rest of the system. However if you ditch the carb and install a tbi unit with O2 sensor then it will probably work even better than before.

 

[Seth S]

An overly rich exhaust will smell like rotten eggs. FYI