Replace cat or rod it out

1989 XJ6 XJ40 vin 576021
Both exhaust manifolds are off and I can easily see inside the catalytic converter.

Catalytic converter guts is all cracked-crumbled on front half of converter. maybe road debris hit it… unknown.

Should I source a replacement or get this off the car and break - rod the rest of the ceramic out?

And then reinstall empty CAT as here in USA old cars only get safety check not emissions.

Looks like a curved “olive” clamp at lower end hope it comes of easy.

Hi 2tone, I don’t know how to answer your question. Sorry. But I do want to comment on your note about how old car inspections are handled in the US, just for clarity. There are no uniform rules for safety and emissions inspections across the whole country. These are governed by each state.


Hi, I don’t think I have a great choice, seems emptying the CAT of its failed contents may be the best option… was wondering if anyone had done this and how hard it was to remove contents. On outside the cat looks in good shape though I can not see it some road debris may have hit the front of CAT causing the contents to break up.
Anyone clean out their cat?

Cats can disintegrate with age. Some, you can shake most of the matrix out by hand.
If „legal“ I‘d rod it out, and the olives are generally not a big problem, bolts/ nuts can be (use exhaust sealer to put it back together).
What I don’t know is if the lambdas like it, but that’s easy to find out online.

I’m not sure how you car’s ECU will report the non-functioning of the cats (IIIRC 1989 used O2 sensors for mixture only).

OBD II cars (1996 and later) have an ‘extra’ O2 sensor to monitor cat performance.

I know in NY there is no tailpipe sniffer any more. But a Check Engine light or recenclty reset ECU is a falure.

‘89 would not be OBDII…no catalyst function monitors.

only 1 OBD sensor ahead of CAT and no check engine lights or VCM warnings. think 90 and up cars had OBD ports not my 89

…and those 90 and up cars (to 94, end of production) have a proprietary port config that only the massive dealer system accommodates, so basically useless unless you have one of those and like to spend time dicking around with it instead of driving.

Pull the cats, no prob.

Not true in California which has SMOG checks back to 1976 model years. No safety check on any year cars,

In Virginia, only cars in certain congested areas must pass emissions test before registration can be renewed. All cars must pass yearly safety test. One can get an antique car registration that waives both of the above testing requirements, so long as the car is at least 25 years old, the registrant has access to another daily driver, and the car’s usage fits the antique car rules.

I removed all the cats from my ‘92 ‘40 with no detrimental effects, I also removed the main cats from my brothers X300, that car is still in service with his cousin-in-law at well over 300,000 klms on the clock.
With my 4.0 litre, I had the opportunity to have it emission tested (not a requirement here in NZ for these cars) and it would have passed even without the cats. The X300 seemed to rev a bit free’er from what the brother reported.

No emission, safety or any other kind of passenger vehicle testing in BC Canada any more - right-wing govt sold off the testing station properties at massive profit to real estate carpetbaggers.

That’s funny Larry! When I lived in FL, emission tests were required until Gov. Jeb Bush’s administration convinced the federal Environmantal Protection Agency that emission testing was no longer needed because air quality had improved.

Robin, this is interesting. Removing the cats should have a positive impact on fuel consumption. So, it may be a good idea to remove the cats when they fail rather than replace them. :thinking:

Gents …

Here in Texas no emissions tests for car’s over 25 years. Why?

Well it seems it’s not out of the goodness of their hearts but rather all cars 25 years and newer have OBD2 systems. So they just plug this into their readers and get the emissions information. The benefit for the inspection centers is that they no longer have to use and maintain the expensive rolling roads (with the sensor stuck up the exhaust).

When you removed the CATS dis you clean out the housing (rod it out) and or put in replacement pipes… on the XJ40 the CAT has the O2 bung… on internet a CAT salvage video showed the ceramic as being a bit soft… smaller pieces hand crumbable… so maybe not so hard to crush -break it up… out of the CAT housing… thoughts?

B New York

Mine were the same in my 88 XJS, a crow bar and shop vac cleaned them out nice. Wear a mask!

Didn’t notice much difference, except a little bit better exhaust sound, and now my exhaust smells like a 60s car. But you get used to it.

so you removed the CAT then started breaking it up and using a shop vac… not doing it on the car?

What state are you registered in that doesn’t check the emissions?

I have a 94 XJ40 with a set of cats that I opened up and removed all of that precious metal then had the cats welded back up. Later on after speaking to Roger Bywater who showed me the error of my ways, correctly informed me that instead of just welding the cats back up I should have welded a simple straight pipe through it first, then weld the outer skin back. The reason being, the exhaust air coming from the manifold will expand in the open space of the cats and then have to recompress to get get through the exit pipe, makes sense.

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My cats were in perfect condition. I took the cats to the bench and carefully cut out the top of the cats so that if any snoopy inspector were to ever look under the car with one of those big mirrors that they use or even just looking at it on a lift it would be undetectable. The only inconvenient problem that I ran into was that it needed to be tig welded and I don’t have a tig welder, but that was it. As I said the earlier post, be sure to weld in a straight pipe.
I did this some years ago and what I did to remove the inside contents are quite hazy now. I don’t remember if I had to use an air chisel or what I did. I do remember that I should have been wearing a mask, though, to keep from breathing in that stuff.