My two cents. I agree. It really sounds like a bearing in very bad shape on its final <1 hour before locking up There are numerous pulleys on which the accesory belt i running. With some luck this is the culprit. At very high mileage any of these or several can cause this problem.
The accesorybelt can be removed easily if you have done it before or see a tutorial video of a few minutes. It is very easy and needs on tool that twists the tensioner pulley center screw too loosen the belt when you flip it of any pulley.
Then with the demonstrated noise level the bad bearing will probably reveal itself when you turn all the pulleys. Spinning them and listening should be enough. They should be silent and no roughness should be felt. Also feel for play. Should be very small . Listening to the bearing housing with a cheap mechanic's stethoscopes is agood idea if in doubt.
I use a electronic one with earphones that cost below 20$.
The followinng parts should be rotated. from the top of the engine
Yeasy too google this and look for "images"

1. The power stering pump pulley
2. The idler pulley
3. The tnesioner pulley
4. The Fan with the fan bearings
5. The Alternator
6. The AC freewheeling bearing that spins when AC compressor is off

Any noisy or bearing with larger play should be adressed. Exchange it for a new device or exchange the bearing for a good quality one. There are lots of really bad stuff out there with questionable bearings that you can buy cheap.
By OEM parts if possible OR reputable company parts. If generic bearings are used it is important that the mech doing it has the needed knowledge. The Bearing Jargon, Bearing types, Seal types, play grades etc.
A good thing is that if the bad ballbearing locks up you will be stranded very suddenly but the engine will survive if you stop engine and pull over immediately when belt fails.

IF the noise on the other hand is coming from the timing belt drive parts things are really serious and has been for a while! . I would not run the motor for one more minute. If bad bearing locks up you will probabaly make scrap of the engine in a fraction of a second
It is some work to just get access to the parts and it needs good instructions OR experience or prefferably a good measure of both and a few hours of work.
This belt drive system has three pulleys/idlers where the ballbearings can fail. The tensioner device, the idler and the waterpump bearings. IF you spend hours of work to get in there to check these it is smart to put in a full kit with all New parts in my opinion.
AISIN sells a kit I have used twice and it seemed to be the correct parts at a good price.

 

+1 that sounds wonderful lol. How long has it been like that? The car is screaming at you that there's a problem. When was the last time the timing belt\associated parts were serviced?

Aisin sells the correct kit with all of the correct parts which are needed, up to OEM specifications.

Careful for counterfeit parts. Careful of the Ebay listing for 25% cheaper than everything else...

Sadly those timing\drive belt things making the noise might not be the cause of the CEL codes. That might just be an entirely separate thing.

 

Misfire is the real problem. Don't worry about the oxygen sensors and VSC for now. Also, serious engine faults automatically turn off VSC, so it could be just that.

Most likely cause of misfire is ignition coil. Move the ignition coil for cylinder 4 to a different cylinder and see if the misfire code moves with it. If so, you've found your misfire problem.

Get real Toyota ignition coils -- if money is tight, get used ones on eBay. There are good, cheap (priced) off-brand ignition coils on Amazon, but it's difficult to figure out which are which, especially since reviews tell you that they work on installation, not what happens a few months later. You're generally safer with a used Toyota coil than a new off-brand coil.

If it's not the coil, I'd suspect head gasket (lack of compression) or fuel injector. But trust me: it's the coil.

By the way, keep driving with that misfire and you'll ruin your catalytic converters. That gets expensive real quick.

 

So I hand spun the pulleys and I didn't hear any noises so I guess it's the timing belt? I seen the Aisin kit on Amazon when I searched for it using my car details but it says it doesn't fit

 

The Aisin Timing Belt kit TKT-021 can be gotten at Rock Auto for $184.79. It should be good for the 2000 ls400 as well. It comes with the idler pulley, the tensioner pulley, the water pump and the gaskets for the water pump along with the new timing belt.
There is a how-to for the '98-00 ls400 (with VVTI) in the FAQ. The images are hosted on Flickr.

And it's probably well worth your time to read through the how-to that Banshee365 did on the 95-97 timing belt DIY.

https://www.clublexus.com/forums/ls-...-belt-diy.html

It's very detailed and covers many parts and operations that are directly applicable to the 98-00 ls400's as well, like torque values, great photos of locations of parts and other bits of wisdom from one who's been there and done that. Highly recommended.

 

Yeah. There's a very strong possibility that all the bad seals you have in the valve covers are leaking oil into the spark plug tubes and fouling the coils. judging by all the accumulated dirt around your valve covers, yours are long overdue for new seals. As for the noises, my thought was bad water pump, which means another timing belt job, but it could be any of the rotating parts in the front of the engine. You need to nail that down.

 

As far as I know the only difference between the Timing kit for the 1995 to 1997 and kit for the 1998 to 2000 models that I have one each is the teeth number on the timing belt . One is 209 teeth and the other is 211.
You should find both available.

 

I don't see Denso ignition coils on Rockauto is there a another I can go with on Rockauto

 

If I was forced to choose on Rockauto I'd go with NGK.

 

THanks. I don't have a 100+ to spend on a coil plus other parts

 

I'm sorry but this isn't a Corolla - it's going to be expensive to maintain. And cheeping out & buying aftermarket **** will ruin the car. It'll just be problem after problem.

I'm sorry that money is tight - I'm just being real with you. It's a durable car, it will last a million miles. But it takes a lot of looking after and parts aren't cheap. It's a 23 year old Mercedes S class competitor, sometimes you need to write a big check to fix 1, 2, 3, 4, 5 parts that have failed.