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No vacuum to vsv valve

Code po401

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6 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE:

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Posted on Jan 02, 2017

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Mustgo
  • 2361 Answers

SOURCE: po401 and po420 (95 toyota previa Van super charged engine)

Check for air leak into system after MAF.

Check for

vacuum leaks on intake manifold,

the air tube between the air filter.

intake manifold vacuum hose.

===
clean throttle plate with Berryman carburator cleaner

SEE sample picture HERE
===


Check for loose or no connected vacuum hose(s).


Take it for a test drive.


Please rate my answer if it's useful to you.


Cheers,

Mustgo

Posted on Dec 19, 2009

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Mustgo
  • 2361 Answers

SOURCE: 1997 pontiac grand prix se has code po401. I

Check for

vacuum leaks on intake manifold,

the air tube between the air filter.

intake manifold vacuum hose.

===
clean throttle plate with Berryman carburator cleaner

SEE sample picture HERE
===

Also remove carbon built up behind the EGR valve and the EGR passage tube.

===

Vacuum leak WILL offset the intended 14.7 to 1 air fuel ratio.

More un-metered air (leaks) will lean out the fuel mixture.

Use small amount of Berryman carb clearer at potential air leak area will help you identify trouble spot.

At idle,just spray and listen for the RPM surge.

The in-rush of carb clearer will increase the RPM on the motor.

Record the problem spot(s) and address it later.

===

EGR carbon built up require 2+ hours to clean from start to finish.

You will need a new EGR base gasket before your start.

Locate and remove the EGR valve after the vehicle is cool down.

Carefully record the connector and vacuum line (for older vehicle) location by drawing an easily to follow diagram.

Remove the EGR valve.

Inspect the location of the carbon built-up inside the valve and the EGR passage tube.

SOAK these areas with WD-40 spary.

You will need a small screwdriver,cloth hanger and lot of newspaper and time to get this cleaning done right.

RE-SOAK the carbon and let it sit for over-night will also help.

One the last round,pass a shop vacuum of the EGR valve and the passage pipe.

Install the new EGR gasket and connectors.

Allow the vehicle to warm up outdoor to burn up any remaining WD-40.


Take it for a test drive.


Please rate my answer if it's useful to you.


Cheers,

Mustgo

Posted on Dec 19, 2009

redbeard00
  • 957 Answers

SOURCE: have a 99 ford ranger keep getting code po401

The MAF sensor could affect the EGR valve but I would look at the MAP first. You may have an exhaust leak you don't know about. Unfortunately without looking at live data or doing component testing you will play the parts change game.
Some components can be tested by most part stores, so ask first.

Posted on May 05, 2010

Testimonial: "thanks lot having it check on thusday another mec said it migt be in the egr tubes. thanks again. i hope this fixes my truck good site to get some help. "

  • 70 Answers

SOURCE: I have a 99 Windstar 3.8L Keep getting DTC PO401

Does the egr vavle open ? You will need to use a scanner to test the dpfe voltage when the egr valve is energized you should read around 3.5 4.00 volts. Also you could remove the vacume line from the egr valve and with the engine running you should see around 100 rpm drop in engine rpm at least this would indicate the egr valve is capable of flowing egr gases through the system to the cylinders.

Posted on May 30, 2010

  • 492 Answers

SOURCE: Engine started missing and lost

what was the complete egr code definition

Posted on Jan 27, 2011

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1 Answer

I replaced the VSV with the used one but I got 33Ohm when I tested. Now that I have the codes P401 & P446. What is the problem I ran into now?


what was the vacuum switching valve for? but po401 is insufficient exhaust gas flow from e.g.r. valve and po446 is the canister purge control solenoid circuit. what are we working on also this can help me better.

Oct 01, 2014 | Cars & Trucks

1 Answer

Error code 441 need to know how to fix &repair


Here is the definition for the code.
You may need a shop manual for the actual test procedures.


P0441 MITSUBISHI Description The vapor pressure sensor, Voltage Solenoide Valve (VSV) for EVAP, Voltage Solenoide Valve (VSV) for canister closed valve (CCV) and Valve Solenoide Valve (VSV) for pressure switching valve are used to detect abnormalities in the evaporative emission control system. The ECM decides whether there is an abnormality in the evaporative emission control system based on the vapor pressure sensor signal. Diagnostic Trouble Code (DTC) P0441 is recorded by the ECM when there is a malfunction in either the VSV for EVAP, the VSV for pressure switching valve, or in the vapor pressure sensor itself, or when evaporative emissions leak from the components within the dotted line in Fig. 1 below.

The ECM closes the CCV and opens the VSV for pressure switching valve causing vacuum to increase in the entire EVAP system. The ECM continues to operate the VSV for EVAP until the vacuum is increased to a specified point at which time the ECM closes the VSV for EVAP. If the vacuum did not increase, or if the vacuum increased beyond the specified limit, the ECM judges the VSV for EVAP and related components to be faulty.
Read more: http://engine-codes.com/p0441_mitsubishi.html#ixzz26BwvoUBv

Sep 11, 2012 | 2001 Mitsubishi Montero Sport 4WD

1 Answer

CODE PO441 DODGE INTRAPID 2002 EREPAIR


Here is the definition of the code.
Possible causes are a defective gas cap or a leak in the vent system.

P0441 DODGE Description The vapor pressure sensor, Voltage Solenoide Valve (VSV) for EVAP, Voltage Solenoide Valve (VSV) for canister closed valve (CCV) and Valve Solenoide Valve (VSV) for pressure switching valve are used to detect abnormalities in the evaporative emission control system. The ECM decides whether there is an abnormality in the evaporative emission control system based on the vapor pressure sensor signal. Diagnostic Trouble Code (DTC) P0441 is recorded by the ECM when there is a malfunction in either the VSV for EVAP, the VSV for pressure switching valve, or in the vapor pressure sensor itself, or when evaporative emissions leak from the components within the dotted line in Fig. 1 below.

The ECM closes the CCV and opens the VSV for pressure switching valve causing vacuum to increase in the entire EVAP system. The ECM continues to operate the VSV for EVAP until the vacuum is increased to a specified point at which time the ECM closes the VSV for EVAP. If the vacuum did not increase, or if the vacuum increased beyond the specified limit, the ECM judges the VSV for EVAP and related components to be faulty.
Read more: http://engine-codes.com/p0441_dodge.html#ixzz242qD9pXO

Aug 19, 2012 | 1997 Toyota Camry

1 Answer

My 2004 Mazda 3 GT 2.3L is getting a P0446 DTC and is burning through a tank of gas in about 2-3 days depending on the amount of driving being done. My Mazda dealer believes that it may be the fuel pump,...


P0446- Evaporative Emissions Control System Vent Control Circuit Malfunction

Possible Causes:
- Missing Fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- Incorrect fuel tank vacuum relief valve

Code is detected when VSV for pressure switching valve is ON, ECM judges that there is no continuity between vapor pressure sensor, fuel tank and charcoal canister (2 trip detection logic)

The vapor pressure sensor, Voltage Solenoide Valve (VSV) for EVAP, Voltage Solenoide Valve (VSV) for canister closed valve (CCV) and Valve Solenoide Valve (VSV) for pressure switching valve are used to detect abnormalities in the evaporative emission control system.

The ECM decides whether there is an abnormality in the evaporative emission control system based on the vapor pressure sensor signal.

Diagnostic Trouble Code (DTC) P0446 is recorded by the ECM when there is a malfunction in either the VSV for EVAP, the VSV for pressure switching valve, or in the vapor pressure sensor itself, or when evaporative emissions leak from the components within the dotted line in Fig. 1 below.
evaporative_evap_system_toyota.gif
The ECM closes the CCV and opens the VSV for pressure switching valve causing vacuum to increase in the entire EVAP system.

The ECM continues to operate the VSV for EVAP until the vacuum is increased to a specified point at which time the ECM closes the VSV for EVAP.

If the vacuum did not increase, or if the vacuum increased beyond the specified limit, the ECM judges the VSV for EVAP and related components to be faulty.

Aug 26, 2011 | Mazda MAZDA3 Cars & Trucks

2 Answers

1999 toyota RV4 code P0401 EGR is good ,   vacuum line is good , what parts could be check.


It means that the egr valve is working, the problem is a very common one, it's the egr modulator valve and to some extent the vacuum switching valve(VSV) for the egr valve, the modulator is attached to the egr valve, remove it and if air can pass from the bottom port through it is defective, in that case replace it and see if it takes care of the problem, if the valve is ok the egr
vsv should be replaced.

Feb 13, 2010 | 1999 Toyota RAV4

2 Answers

Check engine light came on my 2002 Rav 4. Auto Zone diagnostic code PO446. How should I fix?


Chances are, it's going to be either 1 of the 3 switches that need replacing, a new gas cap or a new charcoal canister. The 2 switches under the hood are the VSV for CCV and VSV for EVAP. The one at the canister itself is the VSV for VSP. This VSV for VSP typically goes bad before the other 2 switches do. Plus, the switches are much cheaper than a new canister. (BTW, VSV stands for vehicle switching valve.)

PO446 is an evap canister code

Oct 28, 2009 | 2002 Toyota RAV4

1 Answer

Po401 and po420 (95 toyota previa Van super charged engine)


Check for air leak into system after MAF.

Check for

vacuum leaks on intake manifold,

the air tube between the air filter.

intake manifold vacuum hose.

===
clean throttle plate with Berryman carburator cleaner

SEE sample picture HERE
===


Check for loose or no connected vacuum hose(s).


Take it for a test drive.


Please rate my answer if it's useful to you.


Cheers,

Mustgo

Sep 05, 2009 | 2001 Toyota Tacoma

1 Answer

Lexus 300 es code 0446


Code 0446 is evaporative purge and vent control malfunctions.

Typically it is a vacuum leak in the evaporative system hose, bad cannister, or bad vsv valve (vacuum switching valve) on the cannister.

To fix the issue, start by checking the vacuum hoses to the canister; if one is bad replace it. If not, inspect the vsv valve by un-hooking the vacuum lines one at a time and check for vacuum. Last inspect the canister for damage, or broken connections. Replace any and all damaged or malfunctioning parts.

I hope this helps you, and I wish you luck on your repair.

I did post this solution to your first request, I hope you get it this time.

May 10, 2009 | 2004 Lexus LS 430

1 Answer

Code 0446,what I have to change???


Code 0446 is evaporative purge and vent control malfunctions.

Typically it is a vacuum leak in the evaporative system hose, bad cannister, or bad vsv valve (vacuum switching valve) on the cannister.

To fix the issue, start by checking the vacuum hoses to the canister; if one is bad replace it. If not, inspect the vsv valve by un-hooking the vacuum lines one at a time and check for vacuum. Last inspect the canister for damage, or broken connections. Replace any and all damaged or malfunctioning parts.

I hope this helps you, and I wish you luck on your repair.

May 10, 2009 | 2004 Lexus LS 430

3 Answers

Code on diagnostics p0401


Code on diagnostics p0401:

What is going on?
Exhaust Gas recirculation low flow detected means that: there is vacuum problem in the EGR system - between the combustion chamber, EGR valve (mechanical - blown up diaphragm or clogged airlets/hoses) , EGR Modulator Valve (mechanical - blown up diaphragm, dirty EG/air filter or clogged airlets/hoses) and Vacuum Switching Valve ((mechanical - blown up diaphragm or clogged airlets/hoses OR electrical - VSV not properly synchronizing with the ECM, for instance).

Effects?
This causes the combustion chamber temperature to increase and produce Oxides of Nitrate (NOx) that is out of an acceptable emission range. This triggers the Malfunction Light (check engine light) to stay on (after a couple of driving cycles)!
Solution: Focus on EGR airways (hoses...) and organs (EGR valve, EGR Modulator, VSV), clean, check or replace the defected one. VSV seems to be criticale as it plays electrical & mechanical function. Once the repair is done, Clear the P0401 code using an OBII scanner.

Dec 21, 2008 | 1996 Lexus LX 450

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