I need to get the SES light off so I can pass inspection. Took the car to Vato Zone today and it threw 1 code, P0450. Description:

EVAP system pressure sensor malfunction
Probable cause

1. Open or short circuit condition
2. Poor electrical connection
3. Blocked canister or failed vent solenoid
4. Faulty EVAP pressure sensor


Anyone ever experiecne this code, or have any idea whats throwing it? Im hoping is just a cheap easy fix like a sensor somehwere. Thanks in advnace

Charlie

 

TTT Anyone know of a cheap shop on the south side to diagnose this?

 

i "think" that's for a bad gas cap...

could be wrong. call a dealership to confirm

 

^^^^ Gas cap is the place to start. If that doesn't work there are a few other options.

 

Found some info for ya


Symptoms

Check Engine Light will illuminate

In most cases, there are no adverse conditions noticed by the driver

In some cases, there may be a noticeable fuel odor caused by the release of fuel vapors
Common Problems That Trigger the P0450 Code

Defective Fuel Tank Sending Unit
Defective or damaged Fuel Tank
Defective Fuel Tank Pressure Sensor, wiring, or computer

Common Misdiagnoses

Fuel Cap
Evaporative Purge Valve
Evaporative Vent Valve
Polluting Gases Expelled

HCs (Hydrocarbons): Unburned droplets of raw fuel that smell, affect breathing, and contribute to smog
The Basics
The Fuel Tank Pressure Sensor is a device that tracks any positive or negative pressure changes in the Fuel Storage or Evaporative Control (EVAP) system. It constantly relays this pressure information to the Power Train Control Module (PCM). The Fuel Tank Pressure Sensor is located on top of the Fuel Tank, or on or near the Fuel Pump and Fuel Gauge Module.

Want to Learn More?
The Evaporative Control system Pressure Sensor code sets when the readings of the Pressure Sensor remain at a fixed value and do not change for ten seconds of vehicle operation after a cold start.

P0450 Diagnostic Theory for Shops and Technicians
The Code P0450 indicates that the Evaporative Pressure Sensor output value is not changing during the EVAP Monitor test and/or the operation of the vehicle. This code uses "two trip" logic, which means that the fault condition must be present during two successive cold starts and vehicle operation.

Common Tests for the Evaluating the Fuel Tank Pressure Sensor

Retrieve the code and write down the freeze frame information to be used as a baseline to test and verify any repair.
Pay very close attention to the Fuel Tank Pressure readings by observing its data stream on a scan tool. Does the Fuel Tank Pressure Sensor work properly? If it doesn't, the system will think that no vacuum is being created when, in fact, there is a vacuum being created that the Fuel Tank Pressure Sensor is unable to read. The Fuel Tank Pressure Sensor is the primary feedback sensor that the Power Train Computer relies on for the leak test data.
Inspect and test the Fuel Pressure Sensor wiring. Verify that there is a 5-volt reference signal from the PCM, a good ground, as well as a good signal return circuit to the PCM.
While observing the data stream change (or lack there of) on a scan tool, test the Pressure Sensor with a Vacuum Gauge while it is connected to the wiring harness.
If all of the above test results are within spec, then the problem may reside in the PCM itself.

 

Its been on for some time now, so Im pretty sure its not the gas cap issue. I make sure to hear it click 3-4 times every time I fill up...I found this on ebay

http://cgi.ebay.com/ebaymotors/SMP-S...item27bd99dd76


Is this the sensor that the code is describing?

 

just because it clicks doesn't mean it's good... there is a rubber seal around the base of the cap that deteriorates after time and causes a small evap leak which can cause the mil to come on... have you tried clearing the codes and see if it comes back on??

 

clear the code and get inspected. you can have 1 or 2 not ready, depends on year model.

It is best to check ECRAP codes with a smoke machine.

 

Thanks for the info about the seal, I didnt know about that. And yes, I have cleared the code out and it comes back on.

 

You aren't understanding what I'm saying. Do you want to pass inspection or fix it?

 

I want to do both. Esp, if its a simple cheap fix. And BTW, I was being totally honest about not knowing about the seal in the cap. I wasnt trying to be a smart ***. I found a replacement for like 15 bucks on ebay.