1997 ford expedition security light flashin . its had a steering column replaced,and a stereo replaced before I bought it. cleared codes snap on code reader ,then weeks later, did it again.

SOURCE: 2001 Ford Escape error code P0402

Ok here is the solution when I had the exact same problem with my 2001 Ford Escape:
Replace:

Idler air control valve
EGR vaccum sylenoid
EGR valve

I did all of this work myself (and as a girl it was not hard at all), it cost me around $170.00 for all of the parts, had it done in less than 2 hrs., erased the codes and have not had a problem since then! I hope this helps you out, cuz it sure would have helped me out when I encountered the same problem.

SOURCE: 1997 lincoln town car check engine light-P0402 code

did you replace the egr valve

SOURCE: what is the wiring color code for a 2005 ford expedition radio

use google. i did and i got this
Car Radio Battery Constant 12v+ Wire: Light Green
Car Radio Accessory Switched 12v+ Wire: Yellow/Black
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Light Blue/Red
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: If equipped, the factory amplifier is located behind the trim panel on the right side of the cargo area.
Car Audio Front Speakers Size: N/A
Car Audio Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): Orange/Light Green
Left Front Speaker Negative Wire (-): Light Blue/White
Right Front Speaker Positive Wire (+): Dark Green/Orange
Right Front Speaker Negative Wire (-): White/Light Green
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Gray/Light Blue
Left Rear Speaker Negative Wire (-): Tan/Yellow
Right Rear Speaker Positive Wire (+): Orange/Red
Right Rear Speaker Negative Wire (-): Brown/Pink

SOURCE: 2001 ford taurus with check engine light on. code

Make sure you replaced the right one there are two sensor's for the coolant, one takes coolant temp and the other one runs the fans for the radiator. Both are located on drivers side of the block. 2 wire leads on each how ever both are different in sending readings to the computer.Both look just alike also. Just make sure you replaced the right one. Or replace both.

SOURCE: the check engine light comes on my 2006 Kia Rio once a week. COde is P0496. I had the solenoid and gas cap replaced ands they said they can't find anything wrong with it. Why does it keep comin

First of all, it does absolutely no good to clear codes without properly diagnosing the code and correcting the problem that caused the code to set in the first place. It will only result in the code returning again and again as you can now see.

You must also know how the system works and what failure is indicated by the code. Please note that fault codes NEVER tell you what parts to replace. Then you must know what conditions in the system cause the code to set in order to perform a valid diagnosis of the system.
failure.

With all that said, let's take a look at the code itself:
Diagnostic Test Code (DTC) P0496 is defined by SAE J2011 as "Evaporative Emission System High Purge Flow".

Purge flow is determined by the Powertrain Control Module (PCM) by looking at the Fuel Tank Pressure (FTP) sensor. When there is little or no purge flow, the FTP sensor will read high pressure. If there is too much purge flow, the FTP will read low pressure.

The code is clearly stating that there is too much purge flow (or low pressure/high vacuum in the tank). The people that have been trying to diagnose this problem apparently do not understand this. Leaks in the system like leaking lines or defective fuel caps will cause the pressure to be too high when it is SUPPOSED to be low and will set a code P0455, P0456, or P0457. Smoke testing and fuel cap replacement is what you do for THESE codes, NOT code P0496.

In simple terms, what is happening here is that the PCM is telling the EVAP system to stop purging and it is continuing to purge anyway. This is usually caused by a stuck open Purge Control Solenoid Valve (PCSV). Now I do not know which solenoid they replaced, but I am willing to bet that they replaced the Canister Control Valve (CCV) also known as the "vent solenoid". Again, this might be a good strategy for the other codes listed above, but not the code we are working with.

The other thing that eats at my craw here is that they are randomly replacing parts, evidently without testing them first to see if they are defective and/or are the CAUSE of your problem. I do not call this diagnosis. I call this "parts-nosis". This is where a technician just starts replacing all the parts in the system untill he finally finds the one that takes care of the problem. And YOU have to pay for it! Not only are you paying for parts that do not fix the problem, but they also have the nerve to charge you for "diagnosis" time to find the problem. Then they wonder why people think that mechanics are nothing but a bunch of rip-offs!

So plain and simple, they are not finding anything wrong with your EVAP system because they are simply looking for the wrong problem. They are looking for a system leak when they should be looking at why the pressure is low or vacuum keeps increasing when the PCM is telling it to stop.

There is pretty much only three things that can cause this code:

> Stuck open PCSV (most likely)
> Defective fuel tank pressure sensor
> Defective or mis-calibrated PCM