Lack of power on M13A engine

Good morning Lambert

My Jimny passed its MOT yesterday but struggled getting through the emissions test - I tmay need a new cat.

My question is - are there any recommended suppliers/brands of aftermarket cats that wont break the bank?

The last one I had was from the local motor factor for like a hundred quid. That was about 9 years ago before we got Ermintrude. It seemed to be okfor what it cost. Nowadays I might be tempted by a genuine one but only because I don't intend to get rid of my beloved car any time soon.

I assume the el-cheapo aftermarket one lasted ok did it?

I assumed so. We didn't keep that Jimny for more than about a year after fitting the cat but it seemed ok.

Binding brakes will feel more loose when hot. Almost not binding as things are real hot. Also they should be pulling to one side when cold, and the other side when braking when hot as the hot brakes will work badly.
If really hot you will also damage the bearings and gaskets and seal rings.
And brake fluid.

I found out my cat was broken from a small rattling noise coming from the exhaust manifold. Listen to it through a stick and found the problem area. just press a wooden stick to different areas of metal on the engine, and listen to the end of the stick. You will be able to isolate sounds that way. If there is a rattle inside the manifold the cat might have gone to pieces and those pieces will travel down and damage the next cat as well.

When i changed my cat I went from driving up from our local sub sea tunnel (-287m / 9,6% incline) in third gear barely 80kmh to driving uphill in fifth and had to stop accelerating at 120kmh. Wow the difference, think i have a race car now

I'll see again with the brakes. One thing I know for sure, is that the break doesn't work on the rear-left wheel (for some reason).
Another thing: the mechanic told me that he's gonna fix it, but first I need to change rear axle with a better one (it's cracked a bit).

Now after reading so many replies, it may be possible to the oil inside the axle/groups to be almost gone (no noise comming from it) or the oil is more dense than before. And this would cause a break, I think.

A quick oil replacement for the rear axle group would do the trick?

And btw, the cat isn't glowing red (hot) after driving a lot (saw this on another topic somewhere).

In the end, I'm starting to think that the problem is not the engine itself (or the cat) and more of a rear-axle issue.