Exhaust Gas Analysis

[Azeem]

Hi, My W211 E-270Cdi is due for Exhaust Gas Analysis. The mileage is 160k (km) It was due in Mar 2016 but dealer didn't do the analysis and set the next due date as Feb 2017.
Could someone let me know how these analysis are performed? I know this much from reading the forums that they check Air to Fuel ratio in exhaust gases (about CO2 or NOx contents) and the gases are not running too rich with fuel or air.
Since I wasn't aware of this during the last checkup of Exhaust analysis, could someone please let me know:
- what is your experience with these analyses and what are the ideal values I should be looking at?
- Can an independent mechanic with Star software be able to do it?
- Do I really require to have these done?

My Car doesn't smoke and is in perfect condition. My oil filter/Airfilter and oil change interval is 7500km (once a year). Diesel in our part of the world has high sulphur content (~500 ppm).

Many Thanks

 

[PobodY]

Isn't this part of the MOT?

If it has been tested, you should have a copy of the figures (and hopefully the target values) for your car. - Unless you've got a problem I wouldn't bother having them tested independently.

 

[daveenty]

Hi, My W211 E-270Cdi is due for Exhaust Gas Analysis. The mileage is 160k (km) It was due in Mar 2016 but dealer didn't do the analysis and set the next due date as Feb 2017.
Could someone let me know how these analysis are performed? I know this much from reading the forums that they check Air to Fuel ratio in exhaust gases (about CO2 or NOx contents) and the gases are not running too rich with fuel or air.

I'm going to make the assumption, rightly or wrongly, that you're not in the UK.

Since I wasn't aware of this during the last checkup of Exhaust analysis, could someone please let me know:

- what is your experience with these analyses and what are the ideal values I should be looking at?

Over here they are done as part of the annual vehicle test (MOT).

- Can an independent mechanic with Star software be able to do it?

Yes

- Do I really require to have these done?

It depends on the law wherever you are.

My Car doesn't smoke and is in perfect condition. My oil filter/Airfilter and oil change interval is 7500km (once a year). Diesel in our part of the world has high sulphur content (~500 ppm).

Many Thanks

You're welcome.

 

[Doodle]

The mechanic doesn't even need a Star machine. Just a gas analyser.

 

[Azeem]

Thanks folks for your help.

I am in South Asia.
The law here doesn't require the cars to go through emission testing and the reason I asked if I really require to have these done was more for proper maintenance of the car only.

 

[alabbasi]

The mechanic doesn't even need a Star machine. Just a gas analyser.

Should he need a gas analyzer or can he just read this through the ODBII port?

 

[DSM10000]

Should he need a gas analyzer or can he just read this through the ODBII port?

Well you are analysing exhaust gas so it has to be a gas analyser!

Any data from the OBD will be Oxygen levels or fuel trim data from the Lambda sensor(s)

 

[brucemillar]

Well you are analysing exhaust gas so it has to be a gas analyser!

Any data from the OBD will be Oxygen levels or fuel trim data from the Lambda sensor(s)

This is correct. The analyser is a probe that is stuck up the exhaust with samples taken at idle, then incremental rev bands, usually 1.5k rpm then 2.5 etc.

Some say that the human nose is as good an analyser as you can get ;^)

 

[Trickythemerc]

This is correct. The analyser is a probe that is stuck up the exhaust with samples taken at idle, then incremental rev bands, usually 1.5k rpm then 2.5 etc.

Some say that the human nose is as good an analyser as you can get ;^)

Depending on what your sniffing for you could be right Bruce