Dina,
It can be very expensive to try to repair a problem by changing parts.  You
need to have
someone actually test the system and find out what is wrong.

Maybe the dealership fixed it for a while, but it has failed again, and it
could either be
the same problem, or a very different one.

The dealership should guarantee their work for a time.  Maybe you should go
back to them
and discuss it with them...

If you cannot get satisfaction, locate a very good and dependable
independent mechanic
in your area.  The AAA website has a list of mechanics that they believe are
good and honest.

It is impossible to diagnose something like this without seeing the car.
Everyone can make
suggestions, but as I said above, changing parts without knowing exactly
what has failed is
a very unhappy and expensive way to do it.

Dina, I can't diagnose this for you from a computer, but I can tell you
that a flashing CEL is your car's way of telling you that your engine
is misfiring severely (currently).  Misfiring will cause the shaking
feeling you noted, plus a loss of power and fuel efficiency.  It will
also damage your expensive catalytic converters if you let it go on
long enough.  The 1999 Lexus ES300 has three converters, and believe me
when I tell you they are expensive.

You do need to have a moderately competent mechanic perform a diagnosis
of your misfiring condition.  I would expect you to pay about $50 to
$120 for this service depending on where you live.  A competent
mechanic (not a parts store employee or just any old neighbor) will
tell you what you need to fix the vehicle after their diagnosis is
complete.  Try and avoid the large or national "chain" auto repair/tire
dealer type stores.  I would suggest asking friends and coworkers for
recommendations to a trusted independent or dealership facility,
perhaps even the name of a trusted mechanic that works at one of these
places.  Be prepared to spend a bit of wise money now, or put off this
problem and pay a lot of foolish money later.

Toyota MDT in MO

Dina, I can't diagnose this for you from a computer, but I can tell you
that a flashing CEL is your car's way of telling you that your engine
is misfiring severely (currently).  Misfiring will cause the shaking
feeling you noted, plus a loss of power and fuel efficiency.  It will
also damage your expensive catalytic converters if you let it go on
long enough.  The 1999 Lexus ES300 has three converters, and believe me
when I tell you they are expensive.

You do need to have a moderately competent mechanic perform a diagnosis
of your misfiring condition.  I would expect you to pay about $50 to
$120 for this service depending on where you live.  A competent
mechanic (not a parts store employee or just any old neighbor) will
tell you what you need to fix the vehicle after their diagnosis is
complete.  Try and avoid the large or national "chain" auto repair/tire
dealer type stores.  I would suggest asking friends and coworkers for
recommendations to a trusted independent or dealership facility,
perhaps even the name of a trusted mechanic that works at one of these
places.  Be prepared to spend a bit of wise money now, or put off this
problem and pay a lot of foolish money later.

Toyota MDT in MO

Comboverfish Wrote:

Ok I punched GS instead of ES.
The GS does show 3-4 on same coil.
http://members.troublecodes.net/crunch/gst.pdf

Vacuum leak?
One of the things in her post was that the shake was worse when stopped
at a light OR using the brake. Maybe a bad vac. assist diaphragm?

Thank you so much! I just called to the dealership where I did replace the
air flow meter and etc. and asked if they have anyone here who they'll
recommend, but unfortunatelly they didn't just saying that is better to go to
the Toyota or Lexus dealership. Last time I went to the Lexus dealership for
second opinion, just asked them to see if I need some parts to replace and
ended up to pay $80 (it wasn't diagnostics) So, I would rather to go to the
independent store, than to those big dealership with plasma tvs and free
breakfast.
I won't able to repair my car for some time (a week?), is it safe to keep it
outside for a while? Or I'll need to fix it immediately? Thank you guys again.
..
PS I'm sorry I can't answer all that specific questions about plugs and
individual coils. I won't understand them even on Russian. You know, it's one
of the women things...