Removing front catalytic converter 1989 XJ40

Hi Gents …

During my recent head rebuild I was tinkering with the idea of leaving the header pipes on when I pulled off the head so I wouldn’t have to remove all the header bolts. I changed my idea when I couldn’t figure out how to get to the top inner flange bolt (the other 3 are easily accessible). Well, the good news there was that all the header bolts came off quite easily and the access wasn’t that bad so that didn’t end up being a problem.

But now that I’m going to replace the front catalytic converter I’m confronted with the same problem.

Has anyone out there done this and have any pointers. I COULD take it to a muffler shop but then it would have beaten me :sunglasses:

I just removed all the cats from my ‘92 I replaced the down pipe ones one at a time with straight pipes and the centre ones with bullets.
Later in its life I had the opportunity to have it tested for emissions (we don’t need it to be tested here in NZ) and the car wold have passed the test.

Robin …

How did you unbolt the front CAT from the headers ?

Sawzall :slight_smile: I was lucky in that at the time I had a Midas workshop. I welded a strap across the two pipes and cut the cat out and replaced with a straight pipe then did the other cat so that the relationship was stable.

Is the 94 different? Can’t say I recognize the layout of the plumbing in the pic …is that the o2 sensor thread at the join?

A Sawzall … Brillant :smile:

Unfortunately even if I could get in there and cut the old CAT away I would still have to find a way to bolt in the top of the new one.

Larry here’s the forward pipe layout on my '89 …


The 94’s layout is a bit different Groove, two small cats in the downpipe instead of one big one.

Still wondering if anyone has removed those 4 bolts on the 2 flanges that connect the CAT to the 2 headers and how did you do it ??

Sorry cant help with that one, my ‘88 didn’t come with cats and t was the weedy 2.9 to boot, can you get to it with a long extension and wobbly joint from below or have you already BTDT?

Thanks Robin …

I really do think I’ve been there and … oh wait BTDT :grinning: (love it).

When I was considering pulling the cylinder head with the headers still attached I was under the car just trying to figure out how to ge at that last flange bolt with no success!

I wonder if I have no other option if I could disconnect the rear of the CAT (easily enough done) and then unbolt both headers with the CAT still attached and pull the whole thing up or done to remove them ?? A lot of extra work but if that’s the only way to skin this cat (get it cat/jaguar … Jezz I knock myself out) well so be it :upside_down_face: