Just put 2 new ignition coils in and car still has rough idle. But everything seems to be happening intermittently, meaning not all the time. Here's where I stand:
Cats have smoked on me twice, but today I ran car for 30-45 minutes and no heating of cats. Rpms jump up and down sometimes at idle. When in Park and Neutral, rpm is around 650, but when I put it in drive or reverse the rpms drop. I didn't notice this before I started having these problems. The engine also skips or might be a misfire. When I accelerate, the car gives a vibration until I go over 1,000 rpm. It did have some power, nothing like the other day when the cats heated up and I had no power at all. And lastly the exhaust gases seem to be really strong, don't know if its typical of these cars.
Crazimofo, do you know the specs for the TPS? Is your check engine light on?

 

OK. Seems like my problem is a misfire, which is causing all other problems such as leaning out(code 25) which caused red cat.
Crazimofo are you getting a misfire? Any putting from the exhaust?

 

i have a check engine light code 25 and traction light(mines comes on both at the sametime. about 5 mins of running the car)
smells
yeah it feels like misfiring or running only on 4-6 cylinders instead of all 8 like it should.
also smell rotten egg smell indicating a clogged cat or too much fuel in the cat.

code 25: does coes the cats to overheat

let me get you the specs..brb

 

you're about to buy a new engine soon.

 

why is that Emerald?
i don't drive the vehicle or run it very long.

 

any updates on this?

 

I'm having a similar problem, except, I don't have a check engine light on, and I don't notice any smoke. I don't know if they are running red hot, but the car is lacking some power.. if floored, it revs up between 5-6000 rpms before it shifts into gear and when driven any length of time over 10 minutes, (give or take) i smell a boiled egg kind of smell and a friend told me it sounds like the catalytic converter... i am tapped out in cash right now, and i'm scared of damaging my motor since its my only car and its at 139,650 miles . How much does it cost to replace the cats (performance as suggested above)?

PS. I own a 95 sc400 NOT an ls!

 

my cars doing the same thing as the original poster of this its a 90 so im going to gut the cats and check the ignition coils ..... it has new plug wires roters and caps.. and it bogs down until it cuts off.

 

last timing belt change was when? might be a timing issue... also check the cap and rotors to make sure they are clean and working correctly and are in time (use a timing light) also check for spark at each wire...

 

ignition coil, search.

 

had a coil wire that got cut in two by my cam pulley. i was in a long construction zone were i had no place to pull over (8 miles) by the time i could pull over my car was running on 4 cylinders and my cat was smoking bad. replaced coil wire and it ran fine. 10k on it since incident, no change in gas mileage, car has 170k on it. get cel that cat is below threshold efficiency every now and again but i just reset it . maybe i was lucky but i never have a rotten egg smell from cats

 

so what are the updates? Or did you fix your problem completely Chinaman?

 

problem was fixed a while ago. it was a bad wire completely burned apart. anyone who has a similar problem with their cats and misfire should check plugs wires cap rotor and coils.

 

mine was a roter blew up and got lodged in the timing belt............ causing it to jump time . that was fun