I dont know what is causing this. COuld it be idle speed? I posted about how my car dies occasionally and now I have more details of how it happens because it happens a lot now. (not dies a lot but the rpms drop a lot) Every time I apply the brakes to come to a stop light or stop sign or just slowing down fast my RPM's drop down to about 150-200 the car bogs down like its about to die and then the RPM's go back up to about 500. That is where it idles and 500 is really low for an Automatic idle isnt it? Does anyone know what could be causing this? Do I need to adjust the idle speed or what? Any help would be great! Thanks

 

Here is some text copied from the factory service manual.

"Idle Air Control Valve (IACV) -- Auxiliary Air Control (AAC) Valve

This system automatically controls engine idle speed to a specified level.
Idle speed is controlled through fine adjustment of the amount of air which
bypasses the throttle valve via the IACV-AAC valve. The IACV-AAC valve
changes the opening of the air bypass passage to control the amount of
auxiliary air. ... "

You may make a quick test of your IACV-AAC in the following way. With the
motor at normal operating temperature, and at idle, switch the A/C from
"off" to "maximum". Keep your eye on the tachometer as you do this. The
idle speed should dip momentarily and then recover. If it does this, the
IACV-AAC is working. If the idle drops and does not recover, the engine
may stumble, falter, and stall. The IACV-AAC may require cleaning,
adjustment, or replacement.

The correct idle speed is...
- 700 +/- 50 (automatic transmission, in Neutral)
- 625 +/- 50 (5-speed)

Here's the factory service manual component inspection procedure for the IACV-AAC.

1) Make this test with the ignition key OFF. Disconnect the IACV-AAC valve harness connector.

2) Looking into the valve connector with the latch at the top, you will see two rows with three terminal positions in each. They are numbered 1-3 (top row, right to left) and 4-6 (bottom row, right to left). Check resistance between the following terminals.
2 and 1.
2 and 3.
5 and 4.
5 and 6.
At a temperature of 68 F, the reading for all measurements should be approximately 30 ohms.

3) Reconnect the IACV-AAC valve harness connector.

4) Remove the idle air adjusting unit assembly (IACV-AAC valve is built-in) from engine. The IACV-AAC valve harness connector should remain connected.

5) Turn ignition switch ON and OFF, and verify that the IACV-AAC valve shaft smoothly moves forward and backward. If NG, replace the IACV-AAC valve.


There are other engine parts which play a role in maintaining the right idle
speed, but the IACV-AAC is the first thing to look at. Good luck!

 

If I was you I whould first look over what Daniel B. said.

To me it sounds like your Mass air flow sensor is messed up and will probably need to be replaced.
If your car has more then say... 50K miles I whould change the fuel filter, PCV{valve}, and give your throttle body a good cleaning.

Do these things and there is a really good chance your problem will be gone. Let us know what happens.