Exhaust from engine - 2000 Land Rover Discovery

EGR (exhaust gas recirculation) valve helps to reduce the exhaust emission of automobiles. It recycles some gases discharged from the engine by returning them to the intake manifold, where the engine can burn these gases again, thus reducing emissions.
The exhaust gas recirculation valve is located in the engine compartment (under the hood). Most engines need exhaust gas recirculation to meet emission standards. If the exhaust gas recirculation valve is broken, the car will not pass the exhaust. My Suzuki Jimny has had such a question before, so I am more qualified to answer this question

what engine is in your vehicle? if its a pinto 4cylinder its inlet 0.2 mm exhaust 0.24mm engine cold if its a v6 engine then inlet 0.35 mm exhaust 0.4mm engine cold if its the diesel then inlet 0.35 exhaust 0.35

It's always in the exhaust, that's what it measures or senses- the remaining oxygen content in the exhaust. So it is somewhere in the exhaust piping, anywhere from where the exhaust leaves the engine, which is the exhaust manifold, to the exhaust pipes leading off from the manifold. If you have a V-6 engine, some manufacturers put an oxygen sensor on each side or "bank" of the engine.
The oxygen sensor is never too far from the engine in the exhaust. Look for an electrical wire or wire set going to a piece sticking out of the exhaust. The main oxygen sensor, or sometimes two sensors, are placed always before the catalytic converter in the exhaust stream. For a different purpose, cars nowadays will also have an oxygen sensor AFTER the catalytic converter but still in the exhaust. The purpose is only to monitor the efficiency of the converter.

Sounds like a blocked catalytic converter. Go to the back of the car and place your hand by the exhaust pipe and feel for exhaust flow. Have a helper accelerate engine speed to check for increase in exhaust flow. Note that driving through water will damage a hot converter and can cause exhaust tubing to collapse resulting in exhaust restriction. Engine must flow exhaust to be able to draw air and fuel to the cylinders. Any restriction will limit power and speed.

Causes
- Exhaust leak
- Improperly installed or loose Exhaust Gas Temperature (EGT)
- Low engine compression
- Corroed fuel injector
- Water in the fuel system
_ fuel filter or water seperator fouled.
When is the code detected?
The P2459 will set if the Engine Control Module (ECM) detects that the average time between completed regenerations is less than a calibrated threshold.
Symptoms- Engine Light ON (or Service Engine Soon Warning Light)
P2459 Description The particulates in the exhaust gases are collected by the Diesel Particulate Filter (DPF). When the filter becomes saturated with particulates, they are incinerated by a regeneration process. The regeneration process increases the exhaust gas temperature, warning the Diesel Oxidation Catalyst (DOC) first, the warning the DPF. The Engine Control Module (ECM) monitors the system with inputs from two Exhaust Gas Temperature (EGT) sensors 1 and 2 and the exhaust differential pressure sensor.

Read more: http://engine-codes.com/p2459.html#ixzz1xGkI9BsX

Read more: http://engine-codes.com/p2459_gmc.html#ixzz1xGjSKrIa

is the check engine light on ! if so it may be a clogged up convertor. here is the symtoms, A clogged catalytic converter reduces the flow of a vehicle's exhaust by creating a constricted and/or blocked exhaust channel, which engine exhaust gases flow through on their way out of a vehicle's tail pipe. By reducing the flow of exiting engine exhaust gases, a condition that creates an increase in engine exhaust back pressure (thereby reducing engine efficiency), a clogged catalytic converter results in a small reduction in engine horsepower. A clogged catalytic converter causes a reduction in vehicle gas mileage.
Fumes leaving exhaust is sulfurous as if it is coming from a rotten-egg is one of the unmistakable clogged catalytic converter symptoms. good-day !

egr, exhaust gas recirculation, the tube runs from the exhaust up to a valve on the intake manifold, it lets the engine reburn unburned fuel in the exhaust

According to the service literature I read, the 2003 Montero Sport with the 3.0 or 3.5 L engine does not have O2 sensors listed even in the maintenance schedule. The 2.4 L engine has it on the exhaust manifold though.
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However, the following lists the par, though for before or after the catalytic converter:

http://www.partstrain.com/store/index.php?VN=4294967180+4294966587+4294964143+&Nr=AND(universal:0)&N=0&Ntt=Oxygen%20Sensor

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I think that $250 to $300 is reasonable if the Oxygen sensors are stuck in there with rust and the threads are preserved by the technician. Oxygen Sensor replacement can be tricky.
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Good luck on this repair.

Exhaust Manifold

REMOVAL & INSTALLATION

2.4L Engine

1. Remove or disconnect the following:
   
   
   
   • Negative battery cable
   
   CAUTION
   Wait at least 90 seconds after the negative
   battery cable is disconnected to prevent possible deployment of the air bag.
   
   
   
2. Heat cowl from the exhaust manifold
   
3. Aspirator valve assembly, if equipped
   
4. Oil dipstick and guide
   
5. Oxygen (O2S) sensor connector and ground cable, if equipped
   
6. Exhaust pipe from the manifold
   
7. Exhaust manifold and gasket from the engine
   To install:
   
   
8. Install or connect the following:
   
   
   
   • Exhaust manifold. Torque the M8 mounting nuts to 22 ft. lbs. (29 Nm) and the
     M10 mounting bolts 36 ft. lbs. (49 Nm). starting from the middle and working
     outward.
     
   • O2S sensor connector and ground cable, if equipped
     
   • Exhaust pipe to the manifold. Torque the nuts to 35ft. (49 Nm).
     
   • Aspirator valve assembly, if removed
     
   • Heat cowl to the exhaust manifold. Torque the bolts to 117 inch lbs. (13
     Nm).
     
   • Negative battery cable
   
   
9. Start the engine and check for exhaust leaks.

3.0L and 3.5L Engines

1. Remove or disconnect the following:
   
   
   
   • Negative battery cable
     
   • Exhaust pipe from the exhaust manifolds
     
   • Oil dipstick, guide and O-ring
     
   • Heat shields
     
   • Exhaust manifolds
   
   
2. Clean the gasket mounting surfaces. Inspect the manifolds for cracks,
   flatness and/or damage.
   To install:
   
   
3. Install or connect the following:
   
   
   
   • New gasket and exhaust manifold. Torque the nuts to 33 ft. lbs. (44 Nm) on
     3.0L engines and 22 ft. lbs. (29 Nm) on 3.5L engines.
     
   • Heat shield, Torque the bolts to 10 ft. lbs. (14 Nm).
     
   • Exhaust pipe to the exhaust manifolds. Torque the nuts to 35ft. (49 Nm).
     
   • Oil dipstick, guide and new O-ring
     
   • Negative battery cable
   
   
4. Start the engine and check for exhaust leaks.

Exhaust Manifold - Removal & Installation3.0L Engine

1. Before servicing the vehicle, please familiarize yourself with safety procedures.
2. Remove or disconnect the following:
   Negative battery cable Heat shields Lower splash shields Exhaust front pipes Secondary air tubes Exhaust Gas Recirculation (EGR) tube Exhaust manifold
   

To install:



Fig. Right exhaust manifold torque sequence-3.0L engine



Fig. Left exhaust manifold torque sequence-3.0L engine

1. Install the exhaust manifolds. Tighten the fasteners in sequence as follows:
   1. Step 1: 15 ft. lbs. (20 Nm)
   2. Step 2: 15 ft. lbs. (20 Nm)
      
2. Install or connect the following:
   Exhaust Gas Recirculation (EGR) tube Secondary air tubes Exhaust front pipes Lower splash shields Heat shields Negative battery cable
3. Start the engine and check for leaks.

continue...

Removal Procedure
1. Disconnect the negative battery cable.
2. Drain the engine oil from the engine crankcase.
3. Remove the exhaust flex pipe retaining nuts from
the exhaust manifold.
4. Remove the exhaust flex pipe retaining nuts from
the catalytic converter or the connecting pipe.
5. Remove the exhaust flex pipe.
6. Remove the oil pan flange–to–transaxle retaining
bolts.
7. Remove the oil pan retaining bolts.
8. Remove the oil pan from the engine block.
Cleaning Procedure
1. Clean the oil pan sealing surface.
2. Clean the engine block sealing surface.
3. Clean the oil pan retaining bolts.
4. Clean the oil pan attaching bolt holes in the engine
block.
5. Clean the oil pan scraper.
Installation Procedure
1. Coat the new oil pan gasket with sealant.
Important : Install the oil pan within 5 minutes after applying
the liquid gasket to the oil pan.
2. Install the oil pan to the engine block.
3. Install the oil pan retaining bolts.
Tighten
Tighten the oil pan retaining bolts to 10 NSm (89 lb–in).
4. Install the oil pan flange–to–transaxle retaining
bolts.
Tighten
Tighten the oil pan flange–to–transaxle bolts to 40
NSm (30 lb–ft).
5. Install the exhaust flex pipe.
6. Install the exhaust flex pipe retaining nuts to the
exhaust manifold.
Tighten
Tighten the exhaust flex pipe–to–exhaust manifold
retaining nuts to 35 NSm (26 lb–ft).
7. Install the exhaust flex pipe retaining nuts to the
catalytic converter or the connecting pipe.
Tighten
Tighten the exhaust flex pipe–to–catalytic converter
or connecting pipe retaining nuts to 35 NSm (26 lb–ft).
8. Connect the negative battery cable.
9. Install the oil pan drain plug.
Tighten
Tighten the oil pan drain plug to 35 NSm (26 lb–ft).
10. Refill the engine crankcase with engine oil.