TB45 power loss

Heya, hoping someone can give me some insight on an issue I’ve been having with my GU recently..
It’s a ‘98 TB45 manual. Recently I’ve noticed it to have significantly lost power, it used to fly up hills now it will barely pull 80-100kms even going back to 4th/3rd gear, which it was never like before, an wether my foot is just on the pedal or flat to the floor it doesn’t really make a difference - like I can pump the accelerator from nothing to flat an it stays the same speed (at high speeds/going up hills). I feel like it’s also being really inconsistent with fuel consumption like for the same distance I’ve always driven to say work sometimes it uses way more than it used to, sometimes I feel like I’ve used fuck all. An the accelerator sometimes feels ‘sticky’ - like maybe 1/10 times say after changing gear an first put my foot back in the pedal it feels stiff like it’s stuck so I press my foot down harder an the car jolts (like I’m just dumping the gas) then it’s fine.
The check engine light came on the other day an stayed on consistently for about a week then just turned off an hasn’t come back on - but I have a slight feeling this may have been caused by it overheating a few days prior to the light coming on (an this was due to my belts had come off an hadn’t noticed while I was driving). Another issue in itself, what’s with the seeming common problem of TB’s flipping/blowing belts?? Easy fix but it gets annoying when it’s happened more than I’ve ever heard of before owning a patrol.
Anyway back to the issue at hand I might mention that before all this started happening I had an incident while 4x4ing that my whole exhaust got ripped clean off the car, I did drive it around a bit like this but I’ve since had a brand spanka including extractors put on which you’d think would have made it go better than it did before, on the contrary it was when I got it back from the exhaust shop an started driving it like normal again that I noticed this said lack of power. Also seems to be running quite rich.. I’m about to do a service on it including new plugs and leads, hopefully that will fix the issue but if not does anyone have any idea what else it could possibly be? Might I add it’s got a low half a mill thou kms on it, hoping it’s not on its last legs. My next thought was sensors; MAF, TPS, O2. But I don’t want to spend a fortune for it to be something else entirely. I’ve spent a fortune on it already.
Any suggestions/opinions be muchly appreciated. 🤙🏼

Welcome to the forum mate. Take the time to go to the Introduction section and present yourself to the group.

I would strongly suggest you check the error code that has been recorded by the ECU by the time the CEL was on. It will be your starting point for sure. I suspect you have an issue with your TPS, but again, start by reading the codes.

I don't own a Patrol that long to be able to tell about TBs blowing belts for fun but common sense says your accessory brackets may be bent or misaligned in regards to the crankshaft pulley. Another common way to have belts last less than an oil filter is when the pulleys are worn, such that the belt cloth mesh stays all inside the pulley and that starts the fraying of the cloth mesh resulting in premature rupture.

My first thought is head gasket blown between cylinders.
But It's not my habit to think of computery things... Losing/using oil/water? Any oil in water or vicey versy?

Ol' mate Braz could be onto it with the TPS - it's not getting a good read so not pulling spark timing as needed. and/or overfuelling. Any knocking or pinging?
Does it actually have a throttle cable connected to something or is it fly-by-wire?
Air in fuel lines?

You can buy "sensor cleaner" in an aerosol can. Could be worth taking out what you can get to, hosing them off, checking the connections etc, and doing an ECU reset (after grabbing the OBD codes as said above)

Ah and when you say "it stays the same speed" - do you mean the vehicle? The engine? Both?

If revs increase with no speed increase then it points to clutch slipping

Fuel pump is on way out or dirty fuel filter. maybe