Are cats required?

[cmyoch]

On my newly acquired '84 GL. I noticed the PO replaced the pipe just before the muffler which also has a new O2 sensor in it. There's nothing after. Are catalytic converters a requirement for the engine to run efficiently? I have no problem purchasing whatever is necessary for it to run the best but if I can avoid a cat, I would.

Thoughts? What do you guys have?

Thanks,
_________________
1974 Super Beetle (Factory Sunroof)
1974 Super Beetle Convertible
1984 Vanagon GL (Factory Sunroof)

Jack of all trades. Master of none!

[khughes]

[cmyoch]

[jlrftype7]

[Earl Bay]

Removing the cat didn't change a thing on my dad's 2.1 DJ.
He didn't have much choice anyway because they are nowhere to be found anymore. Bypass pipe, unplug the Lambda sensor and you should be good to go.

[khughes]

[MarkWard]

No reason not to run an OXS with the Cat bypassed or deleted. It should be mounted in front of the Cat. It measures exhaust pre catalyst not after.

[kamzcab86]

[zerotofifty]

Engine runs best with a working oxygen sender. The catalyst is not required except for smog reasons, but lack of a catalyst will NOT harm engine performance.
Keep the oxygen sender, if the oxygen sender is old, replace it as they do eventually become less responsive, when this happens the mixture wont be correct. I replace my oxygen sender every 20 kmiles or so as a routine thing. (factory VW recommendation is every 30k miles per my owners booklet) A great operating oxygen sender is CRITICAL if you run a catalyst to assure longest catalyst life, as poor mixture control can be detrimental to the very pricey catalyst. Correct mixture is also important for optimal engine performance.
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Sorry About That Chief.

Give Peace a Chance.

Words to live by.

[E1]

Easiest way to accomplish this is to empty the cat of its guts and run with the O2. Cat is still there visually…

I support enviro stuff immeasurably… but in this case you’ll have better power and thus better mpg and thus cheaper gas expenses. One must weigh the goods and bads for themselves, but since we’re all just pawns to endless gas price games this is a guilt I could live with.

Our former van blew its cat out from extended injector clogs causing rich running. I went back and forth from the empty Magnaflow cat to a new one of the same model, and it ran so much better on the empty one, on enough less gas, it felt stupid if not wasteful to re-install the working one.

Then there’s the theft risk aptly mentioned by JLRF…

If we still lived in air-weary Denver, I’d never consider not running a cat between tests as to not add to smog. But living in only clean air now, the atmosphere is not the least bit challenged in its own cleanup capacity so may buy a straight pipe to use between tests.

Plus our total weekly water consumption’s about 12 gallons, our fuel use averages maybe 11 gallons, and our total trash around ten lbs.

I once had to remind an over-the-top friend of this, and his resource usages, and his three cars, and his chimney, heating, and air conditioning, and routine backyard campfires, and his kids, when he ragged me for having a “resource-wasting” van. I’ll let you guess where and how he lived.

It never came up again.
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If ever twice as rich, we’re gettin’ a double-wide
’84 “Westfailure”/2.1 Digijet/5.43 Ring & Pinion/Peloquin/D-rated BFG KO2s

AI has spoken to further illiteracy, to steal, to cheat, and to replace humans
The caveman’s first question to the headhunter: “Hey, you got any coffee?”

[MarkWard]

An empty cat can have an annoying resonance. It’s better to add a pipe through the center of the cat. Disclaimer: for testing or off road use only.

[cmyoch]

[cmyoch]

[cmyoch]

[khughes]

[MarkWard]

[Andymon]

[Stinky123]

In the olden days (late 70s early 80s). The car magazines used to bitch about cats putting out a more dangerous chemical than the one that they control.

Modern engines run plenty clean w/o them.

[zerotofifty]

[Abscate]