I am so sick of the SES light!!! I had it on the old car and now on this one. With random techs high flow cats will that cure the problem, or is it just the o2 sims not workin?? I am just sick of the light and I always worry it is something else causeing it, (like my 3rd to 2nd post) How can I sucessfull get ride of it for good!!

 

What's the code number?

 

i just put the slp lt and race pipes w/ sims and i keep getting the light. i have hooked up atap and found nothing to crazy. but i talked with a guy at a speed shop that said if the car doesnt change the way it runs, dont worry about it, heres is what he wrote:
One of the little known problems that people run into when installing
headers is that the O2 sensors no longer function properly. Oxygen sensors
need two things too work properly: lots of heat, and a slow laminar (smooth
flowing) exhaust flow. Long tube headers upset both of these necessities.
The long tube headers relocate the oxygen sensors much farther from the
engine, and the long tube headers accellerate exhaust flow.

During normal operation, your car is constantly adding and subtracting
fuel, swinging back and forth between rich and lean. The engine adds fuel
until the oxygen sensor indicates rich, then subtracts fuel until the
oxygen sensor indicates lean. This process is seen as the oxygen sensor
millivoltage constantly swinging above and below 0.450 millivolts. The
oxygen sensor reading of 0.450 millivolts indicates that the car is at a
perfect 14.8:1 air to fuel ratio. All points above .450 millivolts
indicate that the car is running richer than a 14.8:1 air to fuel ratio.
All points below .450 millivolts indicate that the car is running leaner
than a 14.8:1 air to fuel ratio. As the oxygen sensor millivoltage
constantly goes back and forth over 0.450 millivolts, it is referred to as
switching because the oxygen sensor has just switched from indicating rich
to indicating lean or vice-versa.

The problem that long-tube headers cause is that they do not allow the
oxygen sensor to reach proper operating temperature. The catalyst used
inside the oxygen sensor to detect oxygen needs to be very hot to work.
The cooler the oxygen sensor is, the less able it is to detect oxygen. So,
as your oxygen sensor cools it no longer switches as quickly over the .450
millivolt line. The car now has to subtract substantially more fuel from
operation to get the oxygen sensor to switch over the .450 millivolt line
(this is how the car calculates LTerms as a matter of fact). As the oxygen
sensor cools even more it will begin to go dead. Meaning that the reading
becomes so sluggish that the car cannot subtract enough fuel from operation
to get the sensor to switch over the .450 millivolt line. When this
happens the PCM (your computer) sets the "Insufficient Switching Code".

Luckly, this scenario does not happen all the time. It only happens when
the oxygen sensor does not have enough heat to operate properly, or is
exposed to outside air. This means that certain scenarios are going to
generate this condition. Scenarios in which the oxygen sensor get less
heat than normal are idle, decelleration (because ignition normally stops),
high speed low rpm cruising (because the air passing over the long tubes
actually cools the air), and exhaust leaks.


The Verdict:

If your car is running normal but just occassionally throws this code,
don't sweat it too much. There isn't much you can do about this code if it
is being generated solely by your long tubes. Some people have tried
rapping the long tubes, bushing the oxygen sensors further into the
exhaust. Both of these "solutions" have had limited success though.

This is how cars use to run when oxygen sensors first started coming out.
The oxygen sensor wasn't heated, so occassionally it would just go dead.
The old computers just waited for the sensor to get enough heat again and
started referrencing the O2 sensor again.

If the car only get the code occassionally, then it will still run normal.
The PCM deems that the oxygen sensor is still good enough to use and runs
accordingly.

If your car drastically changes performance when this code is set, then you
have an exhaust leak. The exhaust leak will generatle LTerms at +25%, and
will throw both the lean and insufficient switching codes. When this
happens, your PCM, doesn't know if it burning itself up from running to
lean or if the oxygen sensor is bad. As a precaution your car goes into
"Limp Home Mode". This is basically volumetric efficiency operation in
which the car uses calculated tables, and a pig-rich mixture to get you
home.
Exhuaust leaks that can effect the oxygen sensor are basically any leaks
that are within 6-8 inches of the o2 sensor (either direction).

Good Luck,

 

First you need to pull the codes to see what is happening, that will determine where to start. I had to replace all four sensors and haven't seen a code since.