RWD4life95

Hello all!
1995 Lexus Sc300, well maintained, never had a problem........\
Got gas at a circle K (super premium, BUTb I ALWAYS USUALLY GO TO CHEVRON)) about 45 min away from home, was 15 minutes away and car started to run poorly and occasionally misfire.....
Made it home, It DID NOT even come close to overheating, (half temp gauge max per usual), but did throw a CEL light that has since disappeared.
Car will start fine, and maintain idle under partial load, no unusual sounds from engine or smoke, nothing amiss....throttle increase causes bucking, misfire, and ?sound from catalytic covertor in middle of car
When placed in drive , car will not move , even under full throttle, but does NOT present itself like any transmission problem i have seen in the past
Car has 249,00 odd miles, never abused or run hot, EVER......
recent oil change, oil looks fine as well, no gas odor.........
Thanks in advance for your help, this is great site and an outstanding resource
for those of us who cannot afford taking our car to the dreaded dealer for lighter work or service!!!

ps
I have been searching every combo of keywords and have not found any definitive results.......
If i didnt know the history of the car, i would GUESS Cat Convertor failure, BUT DO THEY REALLY FAIL THAT QUICKLY AFTER FIRST NOTICE OF UNUSUAL DRIVING ISSUES ? (like literally under 30 minutes)

THANK YOU!!!!!!!!!

freakness

Dude,


Check the error codes first.




.

Brennen01

here is a step by step for retrieving the codes

http://us.lexusownersclub.com/forums...ode-retrieval/

RWD4life95

Thanks Brennan for the link.........

Hypothetically, what if the codes were cleared inadvertently by my overzealous roomate's sincere hope to help?
Yes, I let him disconnect the positive terminal for 10 minutes,

Yes, I am an idiot.

Brennen01

lol
try driving it for a little and see if the CEL comes back? it should if you are continuing to have the problems you are describing

RWD4life95

non drivable
will not move in drive at all, sputtery revving even under full throttle, it fights to respond..
engine bay sounds normal
all noise seams to be coming out of the area behind the engine bay/ cat converter area.
Thanks so much for helping!!

Brennen01

does it have any of these symptoms when revving the engine in neutral or park ?

RWD4life95

In park or neutral , it can rev higher when asked ( reluctantly ) although takes A much longer time , throttle response feels/sounds "partially obstructed"

at partial throttle, 2K , 3k , in park and neutral only, engine sounds perfect, no NOTHING


in drive, any throttle application , INCLUDING FULL THROTTLE results in NO REAL RESPONSE, ONLY groping to hold 1K or so TO IDLE
throttle response feels/sounds "Fully obstructed"

If throttle input is stopped, car will stumble severely, and what sounds like a pissed off man inside the muffer/cat area that is attempting to fight his way out with metal javelin will appear
CAR IS PARKED ON A SLIGHT INCLINE FACING UPHILL AT 20 TO 30 DEGREE ANGLE BTW

THANKS

RWD4life95

at partial throttle, 2K , 3k , in park and neutral only, engine sounds perfect, no NOTHING

i meant at STEADY CONSTANT THROTTLE at 2 or 4k

Ramblerman

Your problem realy sounds like a.restriction of some sort to the exhaust. Plugged cats will somtimes glow red, which is easier to see at night. But usually the'll run some what ok when cold till pressure builds up in system, then it begins to choke out the engine, but they' ll idle more or less ok. You could also had broken ceramic in your cat that suddenly moved and plugged the exhaust. We always will drop the exhaust and let.it run open, if the car then begins running ok we know it is a plugged system. Tater up the tail does the same thing!

RWD4life95

error code retrieval failed, Cel light just blinks quickly, no pauses of patterns.....

Is this catastrophic cat convertor failure?

Brennen01

You can take your exhaust off and check down the pipe to see if there are any obstruction in the pipe with a flashlight and also you can run the car with the exhaust just dumping out of the exhaust manifold as stated by Ramblerman.. and if that fixes the issue you know it has something to do with the piping POST cat and if it still does it may by with the cats on the actual manifolds but you stated you are hearing the noises from the middle of the car ish area

Brennen01

i may be wrong.. but there is a sub-cat after the to manifolds meet correct?

Duck05

The SCs are very prone to weird behavior if you have poor electrical conditions and if the ECU starts to go.....

Just to "check the box", you may want to inspect and/or replace your battery cables, the battery itself, and even the alternator. If these check out, you may want to pull the ECU and examine the boards for capacitor leaks.

Good luck - keep us posted...