Jimnys dying

Recently my jimnys been getting slower and loosing torque. Its steadily getting worse. Read the fault codes amd came up with p0135. This is something to do with the o2 sensor. Changed that, cleared fault but no better. Mechanic said check plugs. I did that and they were twice the gap they should be somput a set i had lying to see if it would improve it. Engine smoother but still getting worse. Im about to change them for a new set and new oil/filter. Also gona de gunk oil first too.

Now my first thought was the cat bunged up. But mechanic doesnt think it is. Its an 01 with the g13 engine so no sensor after the cat. Anyone else any ideas

You checked the fuel pump (inside the tank) and its (lack of a proper) filter? after 12 years I imagine it's filled with gunk.

No havent looked yet. Its used alot of fuel so i didnt think it was being starved. But plugs were white so it could be a bit lean..

Service didnt help, and while underneath i spotted gunk round a hub, so thats the kingpins knackered, changed other side last year

Are you sure there isn't a lambda sensor in the cat underneath. My y reg 2001 had one with the g13bb engine. (soft top).

Also is it using water? Had gasket issues can cause a slow loss in power.

I'd go with your first thought, and check if the catalyst is blocked up

Had a long and slow journey this evening coming back from viewing another car. The car got even more slower and started to hear a tiny rattle, by time i got half way back car wont rev past 2500rpm and rattling like mad. So gona rip cat out of her tomorrow. Its pretty much scrap now.

I just hope the cat is the cause of the problem, and not the result of something else