Question about 1994 Cadillac DeVille

2 Answers

Gas cap and service engine lights come on

We have replaced the gas cap, EVAP at engine, the EVAP control at gas tank and the fuel pump. We reset the lights and after 2 days and driving over 200 miles the lights come back. We have had 4 garages do the work listed at considerable expense and still the lights came back.

The engine runs great and we did also replace plugs and plug wires There is 122,000 miles on xar and iy runs great except for the light problem. Any ideas???

Posted by on

2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Master
  • 1,857 Answers

Having the exact year of the car and the codes would help better than just asking us to guess.

Posted on May 28, 2010

Testimonial: "Very good information and we will check as information directs - Thank Very Much"

  • Susan Price May 30, 2010

    There are several reasons you could have a small evap leak. You could have a small intake gasket leak. A hose could be cracked somwhere in the evap system. The charcoal cannister could be defective You have three sensors. A tank pressure sensor, A purge valve and a vent valve.

    Anyone of these could be defective. You could have a fuel filler tube leak. A seal on the gas cap could be leaking or the part it rest on to seal the filler neck could be deformed or cracked. The fuel pmp gasket on top of thegas tank could be leaking.



    What we do is preserize the system with nitrogen and with our smog machine we sniff around to see where gas fumes are escaping. If no leaks are found we remove all three sensors and manually test them. If they all pass we then check to see if there are any technical service bullitins tht may indicate the PCM may need to be reprogrammed.



    You have this listed as a 94 but anything older than a 96 does not have evap codes Thats why I asked for the exaxt year of this vehicle and codes.

×

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Top Expert:

    An expert who has finished #1 on the weekly Top 10 Fixya Experts Leaderboard.

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

  • Cadillac Master
  • 75,822 Answers

There is a pressure sensor on the fuel tank, it is most likely bad and makes the system look like it has a leak to the computer that monitors the sensor, replace the evap system gas tank pressure sensor

Posted on May 28, 2010

Testimonial: "Thanks - Have done the suggested repairs and still have problem - Will check with garage to run computer and check codes. Thanks"

  • yadayada
    yadayada May 29, 2010

    You are 100% sure the gas tank evap pressure transducer was replaced? please be certain of this

×

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2 Answers

I would like to know what the code PO455 on a 2007 Mitsubishi Endeavor means.


Possible causes
- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking
help.jpg What does this mean? Tech notes
The P0455 it's a very common code, because the code is set if the gas cap is loose or missing. Start by tighten the gas cap and clearing the code. In most cases the code can be clear by disconnecting the car battery for about 30 minutes.
help.jpg What does this mean? When is the code detected?
Evaporative Emission System (EVAP) control system has a very large leak such as fuel filler cap fell off, EVAP control system does not operate properly.
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible a noticeable fuel odor caused by the release of fuel vapors
P0455 Mitsubishi Description
This diagnosis detects leaks in the Evaporative Emission System (EVAP) purge line using engine intake manifold vacuum. If pressure does not increase, the Engine Control Module (ECM) will check for leaks in the line between the fuel tank and EVAP canister purge volume control solenoid valve under the following vacuum test condition.
The vacuum cut valve bypass valve is opened to clear the line between the fuel tank and the EVAP canister purge volume control solenoid valve. The EVAP canister vent control valve will then be closed to shut the EVAP purge line off. The EVAP canister purge volume control solenoid valve is opened to depressurize the EVAP purge line using intake manifold vacuum. After this depressurization is implemented, the EVAP canister purge volume control solenoid valve will be closed.

Read more: http://engine-codes.com/p0455_mitsubishi.html#ixzz3NlVyARyX

3022.gif

Dec 30, 2014 | Cars & Trucks

1 Answer

Computer code 455


Possible causes - Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking The P0455 it's a very common code, because the code is set if the gas cap is loose or missing. Start by tighten the gas cap and clearing the code. In most cases the code can be clear by disconnecting the car battery for about 30 minutes.

When is the code detected? EVAP control system has a very large leak such as fuel filler cap fell off, EVAP control system does not operate properly. Possible symptoms - Engine Light ON (or Service Engine Soon Warning Light)
- Possible a noticeable fuel odor caused by the release of fuel vapors P0455 Buick Description This diagnosis detects leaks in the Evaporative Emission System (EVAP) purge line using engine intake manifold vacuum. If pressure does not increase, the Engine Control Module (ECM) will check for leaks in the line between the fuel tank and EVAP canister purge volume control solenoid valve under the following vacuum test condition. The vacuum cut valve bypass valve is opened to clear the line between the fuel tank and the EVAP canister purge volume control solenoid valve. The EVAP canister vent control valve will then be closed to shut the EVAP purge line off. The EVAP canister purge volume control solenoid valve is opened to depressurize the EVAP purge line using intake manifold vacuum. After this depressurization is implemented, the EVAP canister purge volume control solenoid valve will be closed.
if tightening the cap or replacing the cap does not help take your car to a shop to have it diagnosed as it requires special tools/equipment to test this and get an accurate results to find what needs replacing.

Oct 10, 2014 | 2004 Buick LeSabre

3 Answers

I HAVE CODE 0440 MY SERVICE SOON LIGHT ON I FIX FUEL CUP BUT STILL ON LIGHT WHAT TO DO


P0440 - Evaporative Emission Control System Malfunction
Possible causes- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking Tech notes Loose fuel tank filler cap is the most common cause that triggers the P0440 code.

Sep 17, 2012 | 2002 Pontiac Grand Prix

2 Answers

Code po455 2004 chrysler sebring 2.4l sohc G vin code


The code is for a large leak in the fuel tank or evap system.

Some possible cause are - a leaking fuel tank, gas cap, hoses to and from the vapor canister and engine, and a faulty canister.
It's possible a valve is stuck open and allowing the engine to pull fumes in when the system is supposed to be closed, but if this were the case the computer should also set a code for that valve.

Here is the definition.

P0455 CHRYSLER Description The Evaporative emissions (EVAP) system is design to prevent the escape of fuel vapors from the fuel system. Leaks in the system, ca allow vapors to escape into the atmosphere. The leak detection system tests for EVAP system leaks and blockage.


During the self-diagnostics, the Powertrain Control Module (PCM) first checks the Leak Detection Pump (LDP) for electrical and mechanical faults. If the first checks pass, the PCM then uses the LDP to seal the vent valve and pump air into the system to pressurize it. If a leak is present, the PCM will continue pumping the LDP to replace the air that leaks out. The PCM determines the size of the leak based on how fast/long it must pump the LDP as it tries to maintain pressure in the system.
Read more: http://engine-codes.com/p0455_chrysler.html#ixzz24EH3F11s

Aug 21, 2012 | Chrysler Sebring Cars & Trucks

2 Answers

1st code p0440, then code p0453 then p0452 now p0446


This problem is out side the gas tank , has nothing to do with the fuel pump or fuel level sending unit inside the gas tank .DTC P0446 EVAP Vent Solenoid Valve Control System . Do you know anything about automotive evaporative emission system ?
Wells EVAP Training with Sgt Tech P0440 P0441 P0442 etc

This DTC tests the evaporative emission (EVAP) system for a restricted or blocked EVAP vent path. The control module commands the EVAP canister purge solenoid Open and the EVAP canister vent solenoid Closed. This allows vacuum to be applied to the EVAP system. Once a calibrated vacuum level has been reached, the control module commands the EVAP canister purge solenoid Closed and the EVAP canister vent solenoid Open. The control module monitors the fuel tank pressure (FTP) sensor for a decrease in vacuum. If the vacuum does not decrease to near 0 inches H2O in a calibrated time, this DTC sets.

Mar 13, 2017 | 2000 Cadillac DeVille

2 Answers

Obd code p0457 fuel cap replaced mil reset defect not cleared connection checked ok


The code is for a large leak in the EVAP system such as a loose or missing gas cap. But it could also mean a loose or missing hose to the canister or other leak in the tank.
The computer vents the tank several times an hour while the engine is running, and it checks the system by pressurizing the gas tank. If the tank will not hold pressure the code is set.
You may have to check the top of the tank where the fuel pump gasket is, as well as the vent lines to the front of the car.
A mechanic would perform a smoke test to look for leaks.

Jul 23, 2012 | Honda Accord Cars & Trucks

3 Answers

What is code PO496 and PO455 for a 2007 Pontiac Grand Prix mean


P0496 is not alisted code.
P0455 - Evaporative Emission Control System Leak Detected Gross Leak (fuel vapors)
Symptoms - Engine Light ON (or Service Engine Soon Warning Light)
- Possible a noticeable fuel odor caused by the release of fuel vapors Possible causes - Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking

Jan 24, 2012 | 2007 Pontiac Grand Prix GXP Sedan

3 Answers

P0456 error code on a 2003 Mits. Galant


P0456 = "Evaporative emission (EVAP) control system leak detected (very small leak)."

Feb 25, 2011 | Mitsubishi Galant Cars & Trucks

3 Answers

What is code P0455- Emissions leak


well you can have o'reillys use the scan tool to clear codes in the computer and the light will go out unless the problem still exists then it will come back on. this code means that maybe something is wrong in the evap system. i have a question for youl. when you get gas do you stop when filling up and the pump kicks off the first time or do you kepp filling a little more each time trying to top it off better. what many people do not know is that you can do this but it is filling the lines of the evap system with gasoline which will eventually cause problems with the system. the evap controls fuel vapors from the gas tank and it can not work if it is full of gas. i am sure you understand gasoline turns to vapor quickly. gas in your gas tank does too. to keep it under control the evap system gathers it and purges it with switches and sensors that can be damaged by liquid gas. so can vacuum lines. they will swell and leak and all of these will cause the system to fail and the computer will set a code and the light comes on. also the gas cap being lose while the engine is running will do the same.if that is the problem you will need a skilled tech to figure out what is wrong and replace it. if your getting gas always stop the first time the pump kicks off. hope this helps and good luck

May 10, 2010 | 2005 Chevrolet Suburban

2 Answers

Error code p0442


EVAP Emission Control System - Small Leak Detected (1.0 mm). This code can be set when 1. fuel filler cap is not completely tight, 2. when various hoses get punctured or the canister close valve does not seal completely, 3. there is an actual leak in the charcoal canister, fuel tank, or other EVAP system component, 4. if any one of these components are malfunction (a), fuel tank pressure sensor, (b) purge control solenoid valve, (c) canister close valve, or (d) fuel cap. An engine vacuum leak would not set this code.
Solution: Take the vehicle to a Hyundai Dealership for proper diagnosis/repair.

May 23, 2009 | 2001 Hyundai Santa Fe

Not finding what you are looking for?
1994 Cadillac DeVille Logo

240 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cadillac Experts

yadayada
yadayada

Level 3 Expert

75822 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8202 Answers

Are you a Cadillac Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...