As im sure some of you may seen i had a post regarding having a bad CAT
so i guess i was pretty much lied to and had my money stolen because i they changed my cat and it did absolutely nothing.


Basically my car starts fine but once i start driving and give it some acceleration is hesitates and stutters/sputters almost as if its misfiring as well as a bit of minor jerking motion.
It doesnt seem as if its damaging the engine when this occurs might just be fouled plugs.

So my question is has anyone else experienced this problem? ive used the search function extensively and it seems the most similar problems other sc300 owners experience the same type of misfiring/jerking motion after they have washed their engine bay

i havent washed my engine bay or anything but it makes me think as if i need a basic tune-up to solve this problem.
any second opinions?


also would my car react like this if possibly my fuel filter is clogged?

 

I'd siggest to go ahed and do a major tuneup.You will beat your self do death looking for the answer. At least after tuneup you will narrow it down.

Oh yeah change the fuel filter anyway.

 

pretty much what i was thinking, i appreciate the input as well LEX MAN.
I kinda know where im going with this but definetly like the reassurance of fellow lexus owners.

Has anyone else experienced this kind of stuttering/jerking under acceleration???

 

+1 for a tune up..... is the jerking consistant? or only though a certain RPM range?

 

also i just checked around and i noticed in another forum someone seemed to experience very similar problems and they said that their EGR was actually clogged. Could this be a possibility since i did throw an EGR code???
how would a clogged egr valve make my car react?

i was under the impression that if egr was the problem it would throw the code almost immediatly after resetting it and doing a test drive

EDIT(to answer JDMparts) It was consistent at first around 15-35 mph now its very inconsistent and growing worse it seems. It even sputters at idle now

 

Seafoam or Carbon Eater....

Carbon Eater is the same as Sea Foam but it DOESNT break off carbon in chunks... it breaks it down on the molecular level... or so i've read

 

my car only has 95000 miles i kinda doubt its in need of a seafoam. im sure it could benefit from it but i dont really see carbon buildup being the cause of this specific issue.

Anyone had an egr valve go bad and cause such a problem like this???

or should i just give it a tuneup and go from there.

as well im pretty much only knowledgable on american muscle but on an sc300 is there any specific specs the spark plugs need to be tightened in to?
or can you just go with the general rule of handtighten + quarter turn?

thanks for your input as well JDMparts.

 

anyone ever ran into a clogged EGR valve?

 

Hmm I am not defending the shop that swapped out your cat... but what you do describe can be caused by a bad/clogged cat. Do you know if the car is burning oil? has it been over filled with oil before? how often do you change your oil? also the whole thing about a tune up will help out too.

 

i just changed the engine/differential/transmission fluids within 250 miles.

I disconnected the egr valve and the problem persisted exactly the same.

so my next 2 educated guesses are fuel filter as the fuel filter looks completely 1992 oem and/or my sparkplugs.

it seems my spark plug wires are in good condition i pulled them and checked the connection and its clean all is well there.

im stumped guys..... HELP

 

I'm guessing your distributor cap and rotor button have been changed?

 

no they seem to be original would this be the culprit?

 

EGR can cause it to studder if it is stuck open slightly. I forget which vacuum hose is supposed to open the valve, but to check proper operation hook up a vacuum pump to the EGR vacuum hose and see if that recreates the problem.

old cap and rotor and 95K...might as well swap that along with the wires and plugs. Run some fuel injector cleaner through there (Techron is my preference) and that fuel filter. My money is on the EGR though.

 

what did you do to disconnect the egr valve? if you just took the vacuum line off, then that means youve got a vacuum leak and thats whats causing the shuddering.

 

i had very close similar problems.... i started with new plugs, spark plug wires, distributor,rotors, and last but not least COILS! and problem fix. no more sputtering, lagging,misfiring... Maintainance!