Question about 1990 Buick Riviera

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Did not pass emission

I failed emissions today due to the fact they said Nitrogen Oxide failure "Exhaust Gas Recirculation (EGR) System"And gave me a list of probable causes where shuld I check first and what to do?

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Have a professional replace it with a new valve, Be sure that the shop cleans the EGR passages when the EGR valve is replaced. If the EGR system ports are not cleaned, the new valve is at risk of premature failure.

Posted on Jan 06, 2009

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What is the use in AGR of ingine and what is the meaning?


EGR?
Exhaust gas recirculation.
It's designed to reduce the emissions of your exhaust, in your leaded, unleaded or diesel fuel driven vehicles. Exhaust has nitrous oxide in it, and EGR is designed to reduce that nitrous oxide.

Mar 26, 2015 | Cars & Trucks

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Failing emissions testing due to high NOX (oxides of nitrogen)


I have seen several people posting emissions failures due to high NOX (oxides of nitrogen). Nox is created when the engine's internal combustion temperature gets to high.

Two reasons this can occur is improper coolant levels and a malfunctioning egr system. The egr system injects exhaust gas from the exhaust and uses it to line the cylinder walls.This in turn reduces the combustion chamber size and internal combustion temperatures. Ultimately this reduces the amount of NOX created. These systems functioning properly can be the difference in passing or failing your emissions testing because of high NOX ppm.

on Jun 18, 2010 | Chevrolet 1500 Cars & Trucks

1 Answer

Erroe code po405 on my car


Hello.
The error code PO405 = EGR, ( Exhaust Gas Recirculation ), sensor A circuit low input.

What the EGR does;
EGR = Exhaust Gas Recirculation system
Recycles small amounts of exhaust gas from exhaust system, 8 to 10 %, and mixes it with intake manifold air going into the combustion chambers. The addition of this inert, or non-combustable exhaust gas limits the peak combustion temperatures to a range that is below 2,500 degrees F, where the formation of nitrogen oxide, ( NOx ), is known to occur.

Here's a picture of an EGR valve to help you locate yoursem1cl_1.jpg
You may find that you just have a lose hose, or you may have a small vacuum leak.

I hope this helps you.
Donnie

Mar 09, 2011 | Ford Focus Cars & Trucks

3 Answers

96 ford explorer failed emissions test with codes p0401,p0402,p0755,p0756


P0401
EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen. There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor EGR (DPFE). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0401 code means that OBD detected an insufficient amount of EGR.

P0402
EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen. There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor (DPF). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0402 code means that OBD detected an excessive amount of EGR.

There sound like a bad EGR and need replace it.

P0755 Shift Solenoid B Malfunction and P0756 Shift Solenoid B Performance or Stuck Off. First I suggtes check leve fluids and preventive maintenance.

Tell us news.

Sep 02, 2010 | Ford Explorer Cars & Trucks

1 Answer

Vehicle takes 5 minutes to idle by itself. Why?


An inadequate functioning egr system.The exhaust gas recirculation valve uses spent exhaust gases to line the cylinder walls with burnt gases.The purpose of this is to keep the cylinder temperature lower to reduce emissions of oxides of nitrogen.

Jun 01, 2010 | 1990 Pontiac Trans Sport

1 Answer

The car dies sometimes when idle and sometimes when traviling at


he EGR valve, or Exhaust Gas Recirculation valve, is a vacuum controlled valve which allows a specific amount of your exhaust back into the intake manifold. This exhaust mixes with the intake air and actually cools the combustion process. Cooler is always better inside your engine. The exhaust your EGR valve recirculates also prevents the formation of Nitrogen related gases. These are referred to as NOX emissions, and are a common cause for failing emissions testing. Unfortunately, your EGR valve can get stuck, causing NOX gases to build up. You'll know if your EGR valve is stuck or malfunctioning because your car will experience symptoms like rough idle and bucking on accelertaion.

Aug 21, 2009 | 1996 Dodge Grand Caravan

3 Answers

FAILED EGR VALVE


The EGR valve helps your car more efficiently and completely burn fuel by recirculating a portion of your exhaust and running it through the combustion process again. This results in a cooler, more complete burn of the fuel which decreases you car's noxious emissions by prohibiting the formation of some harmful gases.

The EGR valve is vital to your car's emission controls.

When the EGR valve goes bad, it must be replaced - it cannot be repaired.

  • EGR Valve = Exhaust Gas Recirculation Valve.
  • The EGR valve controls formation of noxious emissions.
  • Rough idle and poor acceleration can be caused by a faulty EGR valve.

  • The EGR valve, or Exhaust Gas Recirculation valve, is a vacuum controlled valve which allows a specific amount of your exhaust back into the intake manifold. This exhaust mixes with the intake air and actually cools the combustion process. Cooler is always better inside your engine. The exhaust your EGR valve recirculates also prevents the formation of Nitrogen related gases. These are referred to as NOX emissions, and are a common cause for failing emissions testing. Unfortunately, your EGR valve can get stuck, causing NOX gases to build up. You'll know if your EGR valve is stuck or malfunctioning because your car will experience symptoms like rough idle and bucking on accelertaion.

    The only short term problem is a decrease in gas mileage - but it should really be replaced before sensors become sooted or your cat. convertor gets overworked prematurely.

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    Apr 15, 2009 | Chevrolet Impala Cars & Trucks

    1 Answer

    1995 mercury villager check engine code p1200 injector open


    P0400 = EGR Flow
    P0325 = knock sensor (Do not ever change a knock sensor, they don't affect anything and cost $600 to replace for absolutely no gain)
    P1200 = I can't find this one. I think it's injector flow
    report back on what you find.
    Egr flow may be plugged egr passages or a bad solenoid.
    --------------
    1996 PCED OBDII-Villager SECTION 1B: Description and Operation
    Exhaust Gas Recirculation System
    Exhaust Gas Recirculation (EGR) System Operation The exhaust gas recirculation (EGR) system (Figure 1 below) recirculates a portion of the exhaust gases into the intake manifold under average vehicle driving conditions to reduce combustion temperatures and exhaust gas NOx content. The amount of exhaust gas recirculated varies according to operating conditions and will be cut completely under:
    • Engine starting condition
    • Low engine coolant temperature condition
    • Excessively high engine coolant temperature condition
    • Engine idling condition
    • High engine speed condition
    • Mass air flow sensor failure
    The exhaust gas recirculation (EGR) system on the Villager uses the exhaust gas recirculation/evaporative emission (EGR/EVAP) control solenoid valve to provide vacuum to both the EGR valve and the EVAP canister when commanded by the PCM. If the exhaust backpressure is sufficient to close the EGR backpressure transducer valve, vacuum is sent to the EGR valve and allows EGR gas to flow into the intake manifold. If the exhaust backpressure is not sufficient, the EGR backpressure transducer will remain open and allow vacuum from the EGR/EVAP control solenoid to vent to the atmosphere.
    The EGR system monitor, for OBD II regulations, uses an EGR temperature sensor to monitor the EGR system. The EGR temperature sensor is a thermister located in the EGR passageway. When hot exhaust gas is recirculated into the engine, the temperature at the EGR passageway increases. This increase is sensed by the EGR temperature sensor and a signal is sent to the PCM to indicate EGR flow. If the EGR temperature sensor does not detect EGR flow when commanded by the PCM after two consecutive drive cycles, the malfunction indicator lamp (MIL) will be illuminated and a diagnostic trouble code (DTC) will be stored. The MIL will be turned off after three consecutive drive cycles are completed with no malfunctions detected. The DTC will remain stored in the PCM memory until 80 drive cycles have been completed without the same malfunction detected in the system.
    Figure 1: Exhaust Gas Recirculation (EGR) System Diagram Item Number Description 1 — EGR/EVAP Control Solenoid 2 — Air Cleaner Housing 3 — Throttle Valve 4 — EGR Temperature Sensor 5 — EGR Valve 6 — EGR Backpressure Transducer 7 — EVAP Canister
    Exhaust Gas Recirculation (EGR) Backpressure Transducer Valve The exhaust gas recirculation (EGR) backpressure transducer valve is used to control EGR. The EGR valve is operated by ported vacuum, but the ported vacuum will normally be vented off at the EGR backpressure transducer valve. As rpm increases, exhaust pressure increases and pushes on the diaphragm in the EGR backpressure transducer valve and closes the vacuum vent.
    Figure 2: EGR Backpressure Transducer Value
    Item Number Description 1 — Throttle Valve 2 — Vacuum Port 3 9D475 EGR Valve 4 9F452 EGR Backpressure Transducer Valve 5 — EVAP Canister 6 — EGR/EVAP Control Solenoid 7 — Vent
    EGR/EVAP Control Solenoid The exhaust gas recirculation/evaporative emission (EGR/EVAP) control solenoid (Figure 3) is controlled by the powertrain control module (PCM). The EGR/EVAP control solenoid controls vacuum to both the exhaust gas recirculation (EGR) valve and to the evaporative (EVAP) emission canister. When the EGR/EVAP control solenoid is off (12 V signal from the PCM) vacuum is supplied to both the EGR valve and to the EVAP canister. When the EGR/EVAP control solenoid is on (ground supplied by PCM) vacuum is vented to the atmosphere keeping the EGR valve closed and no vacuum to the EVAP canister. The PCM will command the EGR/EVAP control solenoid on at:
    • Engine starting condition
    • Low engine coolant temperature condition
    • Excessively high engine coolant temperature condition
    • Engine idling condition
    • High engine speed condition
    • Mass air flow sensor failure
    Figure 3: Exhaust Gas Recirculation/Evaporative Emission (EGR/EVAP) Control Solenoid
    Exhaust Gas Recirculation (EGR) Temperature Sensor
    The exhaust gas recirculation (EGR) temperature sensor (Figure 4) is a thermister type sensor that monitors the temperature of the exhaust in the EGR passageway. As the EGR flow increases, the temperature increases. This process creates a change in the resistance of the sensor, which decreases as the temperature increases. The signal is sent to the powertrain control module (PCM) to indicate that the EGR system is working properly. If the EGR temperature sensor does not change resistance as the PCM expects on two consecutive drives, the malfunction indicator lamp (MIL) will be illuminated and a diagnostic trouble code (DTC) will be stored.
    Figure 4: EGR Temperature Sensor Exhaust Gas Recirculation (EGR) Valve
    The exhaust gas recirculation (EGR) valve (Figure 5) recirculates portions of the exhaust gas back into the intake manifold to reduce the amount of the NOx released during combustion and to reduce combustion temperature. The amount of exhaust gases that are released into the engine is proportional to the load on the engine.
    Figure 5: EGR Valve

    Mar 20, 2009 | 1995 Mercury Villager

    2 Answers

    EMISSIONS PROBLEM


    The most likely cause of this is a faulty exhuast recirculation system.It is used to cool the combustion process preventing the formation of nitrous oxide emissions. The main building block of acidic rain.Use your emission diagram and locate the EGR valve.You will need specialized equipment to check it. Other than taking it off and checking for blocked passages from carbon build up there is little you can do yourself.

    Dec 31, 2008 | 1995 Ford Contour

    1 Answer

    Check engine light on - P0400 malfunction


    Exhaust Gas Recirculation (EGR) System The exhaust gas recirculation (EGR) system recirculates exhaust gas into the intake manifold (9424). This lowers combustion temperatures and reduces the formation of oxides of nitrogen (NOX). The amount of exhaust gas reintroduced and the timing of the cycle varies by calibration. Timing and volume are controlled by the powertrain control module (PCM) (12A650). The EGR valve (EGR valve) (9D475) is vacuum actuated. The vacuum hose routing diagram is shown on the Vehicle Emission Control Information (VECI) decal. EGR operation stops when the engine temperature is cold, to improve driveability. The PCM controls the EGR solenoid vacuum valve (9D474). When energized the intake manifold vacuum outlet fitting and cap (9A474) allows exhaust gas to be circulated in the engine to be burned.

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    Oct 20, 2008 | 1997 Ford Aspire

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