Maruti Alto | Increase in Hydrocarbon emissions | Why?

ravin93 · 19th January 2023, 17:42

Hi,
I drive Alto lxi which is now 15 years old. The vehicle is in good condition and serviced regularly from authorized service center.

For all 15 years in PUC check the hydrocarbon emission was hardly 5 - 15, generally less than 50 up till now.
In recent PUC check it came to 265. It's still well within 750 limit, but I wonder what might have changed that caused it to go from 15 to 265?

One small thing I noticed is that at the time of taking reverse to align the number plate with the camera, bit of water droplets came off exhaust which I think is quite normal.

Is there any technical explanation? Could it be quality of petrol? I did it immediately after filling the tank at a petrol station.

Mods - I searched but could not find similar thread, if I missed it kindly merge it with exiting thread. Thanks

audioholic · 19th January 2023, 23:11

Excessive hydrocarbon emission means the presence of unburnt fuel. Was the engine warmed up before the pollution test? Has there been a drop in mileage off late or performance? If the engine was warmed up well before the test then you can get the O2 sensor performance checked through diagnostics in the service center. If that's functioning well it should not allow excess fuel to be injected (rich operation) and if that's okay you can consider repeating the test elsewhere just to ensure there was no wrong reading.

Shreyans_Jain · 19th January 2023, 23:41

If the engine was fully warmed up and the car itself is driving fine, then I suspect this to have more to do with the emission testing equipment and its calibration. Who is to ensure that the numbers you are being given are actually correct and valid? Don’t think too much into this.

ravin93 · 20th January 2023, 04:36

Thanks. @audioholic @Shreyans_Jain

Well the petrol pump and PUC center is even less than a mile from my place and it was a cold engine start. On top of that I was waiting in queue at PUC as there were 3 bikes before me and so I shut off the engine for another 10 minutes or so.

So may be that's the reason.

No drop in mileage. It's around 15 - 16 for quite a while.

As suggested in a months time I will repeat the test at another place and also bit far away so that engine would be warm enough.

Regards.

ravin93 · 10th July 2023, 14:50

I am returning to this thread after 6 months now. I have done the next due PUC now.

This time I drove 6 KMs to another PUC station.

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It's 30 and it's back to where it always has been. In past even on cold engine start it was never > 50.

So I suspect that the PUC machine at other station might have been faulty.

Vehicle is sparingly driven. Hardly 200 KM/month max.

Thanks to you all for your guidance.

x-o-b · 12th July 2023, 06:48

Quote:

Originally Posted by ravin93

Hi,
I drive Alto lxi which is now 15 years old. The vehicle is in good condition and serviced regularly from authorized service center.

Maintenance Checkpoints:

Catalytic Converter
EGR System

Mod Note: Please quote ONLY the relevant bits of a post. Quoting a full, long post inconveniences our mobile readers.

ravin93 · 1st January 2024, 16:32

Thanks @x-o-b for your inputs.

I am returning to this thread again. This time to save time I again went to the same earlier PUC center which I had visited an year ago where readings were much higher than usual.

While all other places readings have always been excellent, once again today his machine showed
0.22 (up to 0.5) and 176ppm (up to 750ppm).

All other places 0.5< and <50ppm

So I definitely conclude that this machine is not accurate or has never been recalibrated.
Best regards.

19th January 2023, 17:42	#1
ravin93 BHPian Join Date: Jun 2020 Location: Pune India Posts: 29 Thanked: 9 Times	Maruti Alto \| Increase in Hydrocarbon emissions \| Why? Hi, I drive Alto lxi which is now 15 years old. The vehicle is in good condition and serviced regularly from authorized service center. For all 15 years in PUC check the hydrocarbon emission was hardly 5 - 15, generally less than 50 up till now. In recent PUC check it came to 265. It's still well within 750 limit, but I wonder what might have changed that caused it to go from 15 to 265? One small thing I noticed is that at the time of taking reverse to align the number plate with the camera, bit of water droplets came off exhaust which I think is quite normal. Is there any technical explanation? Could it be quality of petrol? I did it immediately after filling the tank at a petrol station. Mods - I searched but could not find similar thread, if I missed it kindly merge it with exiting thread. Thanks
	() Thanks

19th January 2023, 23:11	#2
audioholic Distinguished - BHPian Join Date: Jun 2012 Location: BengaLuru Posts: 5,663 Thanked: 19,435 Times	re: Maruti Alto \| Increase in Hydrocarbon emissions \| Why? Excessive hydrocarbon emission means the presence of unburnt fuel. Was the engine warmed up before the pollution test? Has there been a drop in mileage off late or performance? If the engine was warmed up well before the test then you can get the O2 sensor performance checked through diagnostics in the service center. If that's functioning well it should not allow excess fuel to be injected (rich operation) and if that's okay you can consider repeating the test elsewhere just to ensure there was no wrong reading.
	(2) Thanks

19th January 2023, 23:41	#3
Shreyans_Jain Distinguished - BHPian Join Date: Nov 2013 Location: HR51/HR29/HR26 Posts: 2,767 Thanked: 21,322 Times	re: Maruti Alto \| Increase in Hydrocarbon emissions \| Why? If the engine was fully warmed up and the car itself is driving fine, then I suspect this to have more to do with the emission testing equipment and its calibration. Who is to ensure that the numbers you are being given are actually correct and valid? Don’t think too much into this.
	(3) Thanks

20th January 2023, 04:36	#4
ravin93 BHPian Join Date: Jun 2020 Location: Pune India Posts: 29 Thanked: 9 Times	re: Maruti Alto \| Increase in Hydrocarbon emissions \| Why? Thanks. @audioholic @Shreyans_Jain Well the petrol pump and PUC center is even less than a mile from my place and it was a cold engine start. On top of that I was waiting in queue at PUC as there were 3 bikes before me and so I shut off the engine for another 10 minutes or so. So may be that's the reason. No drop in mileage. It's around 15 - 16 for quite a while. As suggested in a months time I will repeat the test at another place and also bit far away so that engine would be warm enough. Regards. Last edited by suhaas307 : 10th July 2023 at 14:56. Reason: Spacing for improved readability
	(1) Thanks

10th July 2023, 14:50	#5
ravin93 BHPian Join Date: Jun 2020 Location: Pune India Posts: 29 Thanked: 9 Times	Re: Maruti Alto \| Increase in Hydrocarbon emissions \| Why? I am returning to this thread after 6 months now. I have done the next due PUC now. This time I drove 6 KMs to another PUC station. It's 30 and it's back to where it always has been. In past even on cold engine start it was never > 50. So I suspect that the PUC machine at other station might have been faulty. Vehicle is sparingly driven. Hardly 200 KM/month max. Thanks to you all for your guidance. Last edited by suhaas307 : 10th July 2023 at 14:56. Reason: Spacing for readability
	() Thanks

1st January 2024, 16:32	#7
ravin93 BHPian Join Date: Jun 2020 Location: Pune India Posts: 29 Thanked: 9 Times	Re: Maruti Alto \| Increase in Hydrocarbon emissions \| Why? Thanks @x-o-b for your inputs. I am returning to this thread again. This time to save time I again went to the same earlier PUC center which I had visited an year ago where readings were much higher than usual. While all other places readings have always been excellent, once again today his machine showed 0.22 (up to 0.5) and 176ppm (up to 750ppm). All other places 0.5< and <50ppm So I definitely conclude that this machine is not accurate or has never been recalibrated. Best regards.
	() Thanks