Questions tagged [emissions]

The various chemicals emitted in exhaust gasses from an internal combustion engine. The usual gasses which are measured through emissions testing are Nitrogen Oxide (NO2), Carbon Monoxide (CO2), and HydroCarbons (HC).

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1997 BMW M3 Failed Smog with High HC

Has been through twice now and looking for possible causes. 1st test results only the 15mph test failed HC too high. 15mph HC=60 CO=0.12 NO=172 25mph HC=23 CO=0.04 NO=42 Afterwards, I smoke tested the ...
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05 Yukon XL Evap Test Incomplete, Need Troubleshooting Help

I own a 2005 Yukon XL, and I'm facing issues completing the evap test. I've attempted various drive cycles with the gas tank half full, as well as driving for 5 minutes and then idling in park for 5 ...
joe's user avatar
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How does CO poisoning still happen with newer cars?

I'm learning about catalytic converters, and learned that a car with a functioning converter doesn't output carbon monoxide (CO) because it converts it into carbon dioxide (CO2) and water (H2O). How ...
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2002 Toyota RAV4 major emissions issue, multiple sensor faults

I’m having problems with my Toyota RAV4. I bought the car 6 months ago with a lambda sensor fault. By time I got it home, had lambda bank 2, sensor 2 and Mass airflow sensor faults. Changed both, okay ...
LEP's user avatar
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On carbureted vehicles, are vacuum lines exposed to gasoline vapors?

I'm restoring a 1985 Chevy G30 Van 5.7L, but these questions apply broadly to carbureted vehicles. The vehicle is carbureted, and most controls for the emissions system and climate control system are ...
JoseOrtiz3's user avatar
2 votes
2 answers
98 views

Exhaust gas composition from London buses

I asked this on Reddit earlier this week, but nobody had much technical insight. Can anyone shed light on why exhaust gas from a typical London bus smells entirely different from a coach or truck's ...
Jepper's user avatar
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Check beforehand if will pass emissions test?

How can I check, using an Bluetooth ELM327 OBD-II dongle, whether my car will pass an emissions test?
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High HC emissions, CO & NO is ok

I have a 95 Isuzu Rodeo with 3.2. the HC readings are 63 @15mph & 44@ 25mph. I did an oil change, replaced the plugs, wires, 02 sensor, and put in different fuel additives with each gas fill-up. I ...
alzaplaya's user avatar
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144 views

Did I get the right catalytic converter for my Honda Odyssey?

There is an engine code on the bank 2 catalytic converter in my 2007 Honda Odyssey EX-L, I paid for a diagnosis from a mechanic and they recommended replacement of the bank 2 catalytic converter. I ...
pythonweb's user avatar
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1996 Ford F150 (OBD2) fails AZ emissions due to "disabled" EVAP

My 1996 F150 with OBD2 is failing Arizona emissions due to disabled EVAP system. I did not disable it and don't know how it would have been disabled. There is an EVAP canister present though. The ...
jim's user avatar
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Car fails emissions due to not being driven

My mother is elderly and does not drive very much. Her vehicle registration requires an emissions test. When she went to get the test, she was told that the test could not be performed because the ...
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Seeking some specific information about a 1994 Toyota Hi-Ace

I am attempting to matriculate my camper from the UK to portugal and in order to do so they have requested what is known as a "certificate of conformity". Unfortunately i cant get one of ...
bw1984's user avatar
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'16 Mazda CX-5 failing HC-PPM emissions test?

I have a 2016 mazda cx-5 with 25K miles that has to go through a yearly inspection. The vehicle's in good shape, plus I take it the mazda dealer for maintenance. I took it to the the inspection center ...
rbhat's user avatar
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324 views

Why does the California smog check involve an inspection of the ignition timing?

I purchased a 30-year-old truck, which seems to run well in spite of its age. But when I take it to get a smog check, the engineer clips a timing light to the first spark plug and tells me that the ...
Metamorphic's user avatar
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Chemical analysis to detect oil burning in emissions [duplicate]

Is it possible to chemically analyze an engine's emissions to detect presence of oil in the fuel? I am losing a lot of oil but it's not dripping when running to indicate a leak. So I would like some ...
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What are the factors that rev hang depend on? Does rev hand depend on the engine load?

I know that rev hangs are intentionally introduced to modern vehicles that operate on electronic throttle bodies, by programming the ecu to close the throttle valve slowly (in gasoline engines) even ...
Abhishek P G's user avatar
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EGR was deleted. Is this the EGR line?

Someone who owned my 1986 3.8l Mustang before me decided to delete the EGR system. I'm attempting to get this car to pass emissions so I want to reinstall the EGR system. However I want to make sure I'...
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High voltage on downstream O2 sensor after driving, but low voltage on idle

After driving on the highway, my downstream O2 sensor voltage was a steady 0.8V, which is high. On the other hand, when idling before the drive, it was a steady 0.3V. Is it normal for the downstream ...
Asker's user avatar
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What kinds of tuning can ruin a car's ability to pass emissions testing?

Suppose I want to tune a car for performance, like doing an ECU re-map for a Toyota Supra. Could this affect the car's ability to pass emissions testing? If so, how? And in general, what kinds of ...
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Can the OBD II used for emissions testing cause damage to engine or electrical system?

We recently took our 2016 Ford 10 cyl. (Motorhome) to our mechanic for oil change and check up, prior to big trip. Everything looked great and vehicle ran great before and after this visit. We then ...
Laura L Fiorini's user avatar
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Options? Stripped out Threads on a Catalytic Converter-Mounted 02 Sensor in California

This is a multi-part question: First, I would like general input on how a catalytic converter should be evaluated for signs of failure? For example, does testing a CAT to ensure it doesn't have ...
Adobe_User's user avatar
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2012 Automatic Civic firing wrong

I had a question for you all if you'd please help me out. My 2012 automatic civic had its emissions light, VSA light and high temperature lights turn on after I scraped the back rear end on a curb. ...
Courtney Myers's user avatar
2 votes
1 answer
6k views

P0491 Secondary Air Injection System Insufficient Flow. Stumped

My VW CC 2010 is having a CEL with the code P0491 which means the pressure sensor is not detecting enough air being pumped from the intake into the exhaust. No other codes. No problems since this is ...
Salvador Martinez's user avatar
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2k views

Emission High CO and High Lambda

It fails at 2500rpm only with CO 0.5~0.6 and Lambda 1.04~1.05. How can it possible be that emission fails because of HIGH CO, and HIGH lambda reading... It means that engine runs rich and lean at the ...
John's user avatar
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Inspection Not Ready ( 02, 02 heater, cat)

2006 Ford F150 Battery was unplugged before car was purchased. I bought it and put 300+ miles on it and still see those 3 sensors not ready. No codes. Replace all 02 sensors? Diagnose with mech for ...
zngb's user avatar
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Will replacing spark plugs fix this? [closed]

My husband and I purchased a 2011 Mazda 6 2-3 months ago. It had 71,000 mi on it when purchased. One accident, but only cosmetic. A few weeks after driving it, I noticed some jerking when coming from ...
Kimgamez's user avatar
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1 answer
136 views

What is this inlet part on a lawnmower muffler?

I have noticed a small box on the bottom of the muffler on a Mountfield SV150 lawnmower engine. Inside is a reed valve set up as inlet only and a small filter grill. What is the purpose of this part? ...
Daniel's user avatar
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1 answer
3k views

Will my car pass emissions if all monitors pass scanner except EVAP monitor

I had toyota remove a P code off my 2010 1.8L corolla after a repair. I need to pass emissions in Arizona in the next 2 weeks. I went to AZ and they let me borrow the scanner so I plugged it and ALl ...
TRS7's user avatar
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2 votes
3 answers
314 views

Catalytic Converter Clogged, But with what?

So, I've recently replaced my catalytic converter, bank 1 and 2. Both were a pretty penny (About $1,500 Each), I inspected the old catalytic converters and they look to have failed due to being ...
James Vargan's user avatar
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357 views

Volkswagen GTI OBDII Readiness

I have a 2015 Volkswagen GTI SE (2.0T) which is (a little over) due for an emissions test. A few weeks ago I had some rear-end bumper damage repaired, and while in the shop they cleared the trouble ...
brhans's user avatar
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Can anyone provide documentation for the 2011 chevy cruze eco grill shutters?

I'm trying to understand how they work and where the motor is since I am unable to get the plastic off the bottom of the grill to access them directly. Mine seem to move if I slowly torque them ...
Rowan Hawkins's user avatar
1 vote
1 answer
32 views

Where does California publish vehicle emission standards?

When a vehicle is smog tested in California, several components of its exhaust gas are measured. If the levels of those exhaust gas components are within limits (presumably established by California)...
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Over filled oil - 09 Hyundai Elantra

I dropped off my car for an oil change which is an older model, but I always took care of it so it ran great. I listen to the vehicle all the time to ensure nothing seemed off, and no issues. The ...
Anon's user avatar
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-1 votes
2 answers
93 views

Not enough catalyst data for SMOG inspection even after 350 miles

Place: California Car: 2003 Acura RSX Type-S I went on 4 week vacation in Dec, my car sat in garage. Now I have trouble getting my SMOG passed, I am getting catalyst data not ready reading, even ...
Radim Cernej's user avatar
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2 answers
944 views

What is CO2 g/km emissions equivalent of Euro 4 petrol standard?

I am trying to find what Euro 4 standard is with regards to CO2 g/km. All I can find is that it is: CO: 1.0g/km THC: 0.10g/km NOx: 0.08g/km This makes no sense to me when trying to compare this to e....
Asu's user avatar
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4 votes
1 answer
186 views

What should I expect as result of a firmware update fixing NOx emissions in a gasoline engine?

I received an invitation from Peugeot asking me to bring a 2018 naturally aspirated gasoline engine Peugeot 208 (61 kW) to the workshop for a firmware update fixing lamba sensor management which ...
FarO's user avatar
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3 votes
3 answers
3k views

Evap System Leak, Repair and Clear Codes to Pass USA State Emission Inspection?

I'm aware of two related issues here Does Check Engine Light Clear Itself... I need the correct 2010 ... drive cycle steps to clear a “Permanent ” P0456 code I've just completed a particularly nasty ...
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1 vote
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MOT emissions fail

My mini 1.4 petrol has failed on high co and hc but only by a small amount . Last year I gave it a service to pass the emissions but this year it’s not having it. I have fully serviced it, added a ...
Zak Black's user avatar
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0 answers
88 views

Incereased HC in emission test, low CO VW Jetta 1.4 TSI

Yesterday I took my 2008 VW Jetta (1.4 TSI 122ps with 101k km) for annual emissions test. The car passed the test but I noticed that an increment in HC from year to year, especially when idling (...
Mike T's user avatar
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1 answer
394 views

Georgia Emissions Testing Missing Gas Cap "Evap Emission Control Sys Leak Detected (Small Leak)"

I lost the gas cap for my 2008 BMW 328i about a month ago. It took me about a week to get it replaced. During that time, the check engine light for my car lit up. I went out of town right after ...
Lloyd Banks's user avatar
1 vote
2 answers
3k views

Converting emissions readings between ppm and g/km

Having taken my wife's 20 year old Nissan in for it's MOT test last week, I was looking at the results of the emissions test, and noticed that the Hydrocarbon reading was 6ppm - with a limit of 200. I ...
Nick C's user avatar
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Is this MX-5 running too cold, and could that explain poor emissions?

Last year my MX-5 NC struggled to pass its emissions test. 5 years ago I replaced the front cat exhaust manifold with a 4-1 non-cat manifold, moving the oxygen sensors around the remaining mid pipe ...
Richard Parker's user avatar
1 vote
1 answer
90 views

CO and Lambda fail after cleaner, air filter and throttle body clean

Went for an MOT, first test failed on high CO AND HC but normal lambda. Got new air filter, cleaned EGR and throttle body and added a cat cleaner into petrol tank. Second MOT failed due to high CO (...
LionLeon's user avatar
4 votes
4 answers
8k views

Is it possible for an oxygen sensor spacer to cause a car to stall?

VW CC 2010 2.0L CBFA I installed an O2 sensor spacer on my downstream O2 sensor and it seemed to be working for a day. One day later, after the car had cooled down it would rough idle and stall when i ...
Salvador Martinez's user avatar
1 vote
1 answer
8k views

I/M Readiness Test: How to know if I WILL pass emissions test?

My OBD monitor showed all as OK. My manual says that this means "monitor has completed diagnostic testing." During the emissions inspection, will the mechanic just plug a similar device into my car ...
Tom's user avatar
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1 vote
2 answers
25 views

Star Smog Checks

I have an MR2 Spyder with 80,000 miles on it runs great but the check engine light is on and the smog technician stated that even if I reset the check engine light it would still not pass smog no ...
user45984's user avatar
2 votes
1 answer
150 views

My truck failed emissions because they couldn't find the EGR

I just took my 2011 GMC Silverado 2500 w/Duramax in for an emissions test in Utah County. They do more than just emissions test. They look to make sure all the elements of the emissions system are in ...
Francis Lewis's user avatar
1 vote
1 answer
1k views

Emissions - High CO Reading

My 2004 Volkswagon Polo has just failed its emissions test. It has failed on the CO only, everything else is okay. The results are as follows: Engine/Oil Temperature: 92℃ (720 RPM) Low Idle CO 0.32 ...
colmlg's user avatar
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Emissions reading on a 1993 Toyota Corona/Carina E 3SFE 2.0

Are these values normal for a 1993 car? If not, please tell me what should be fixed or replaced. I believe it's running rich based on the lambda value.
Sherwin Diaz's user avatar
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0 answers
28 views

Low idle after adding gasoline

This has happened twice now. My 2000 toyota sienna runs fine until I went to add gasoline. Upon startup, my idle was immediately much lower. I can rev throttle and it sounds smoothly until I release ...
Miguel's user avatar
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