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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37
votes
3answers
338k views

What does a water like drop coming out of the exhaust of the car signify?

Sometimes while driving in the traffic, I come across a car or two which would be dripping water-like drop from it's exhaust steadily in a break of 4-5 seconds. I tried to ask a couple of people at ...
32
votes
7answers
9k views

What is the point of the exhaust?

I was thinking today, what is the actual point of an exhaust? Why can't we just have a pipe going out the front of a car instead of taking all the gases to the back of the car? I can only see ...
11
votes
3answers
8k views

What could cause high HC and CO, but low NO and CO2 in a smog test

Despite my confidence in having a (relatively) new catalytic converter and a new O2 sensor, my lovely 1994 BMW 325i Convertible got flagged as a "Gross Polluter." The test results are summarized below:...
11
votes
2answers
1k views

How are diesel engines better for the environment than gasoline?

I understand that diesel engines have become much more efficient at controlling emissions over the last couple decades. Various websites like this one describe the technological improvements that have ...
11
votes
3answers
14k views

Why don't all diesel engines have throttle plates?

I learned recently that many older and some newer diesels don't have throttle plates to control airflow. I was also quite shocked to learn about a condition called diesel engine runaway. Apparently ...
11
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2answers
2k views

How does raw fuel damage the catalytic converter?

I was wondering, if fuel gets in the catalytic converter, how does it damage it?
8
votes
1answer
4k views

What is the “Activated Carbon Cannister”?

Why do I have an "Activated Carbon Cannister" in my unleaded/petrol car? What is it's purpose? How does it work? Do I need to do anything to maintain it? I would like a general answer, but my car ...
8
votes
1answer
599 views

Connecting to the Battery During Emissions Testing to Measure RPMs?

When doing emissions testing, they connect to the battery, either directly, or using the cigarette lighter socket. I'm assuming that this is to measure the RPMs, as the only other thing connected ...
7
votes
3answers
2k views

Why are VW recalling their cars to remove a defeat device?

As I understand it, Volkswagen had software to artificially enhance their efficiency ratings on a test rig. Since it would only be active under test, what is the point of recalling millions of cars to ...
7
votes
4answers
64k views

What effect will removing my EGR have?

My 2003 Jetta TDI check engine light recently came on, and a scan by Advance Auto revealed code P0401 -- EGR insufficient flow. I took the vehicle to the local TDI guru, who gave me the option of ...
7
votes
2answers
16k views

Should I replace my own oxygen sensor if i have a Check Engine Light and Code P2195?

My 2003 focus lx 2.0L L4 SOHC ~18,000 miles has had the engine light so i went to autozone to read the code. Autozone obd2 printout says "P2195 lack of heated oxygen sensor- Bank 1 Sensor 1 HO2S11 ...
7
votes
3answers
11k views

Emissions - High CO reading only

My 1999 Honda CRV has just failed it's UK MOT test on emissions. Results are below: 1st test: CO 0.73 (FAIL - max is 0.30) HC 78 (PASS - max is 200) Lambda 1.008 (PASS - between 0.970 & ...
6
votes
4answers
736 views

Cheap vs Expensive Fuels [closed]

What is the difference between the cheapest fuels in a place like Tesco's and the 'high quality', highly priced competitors? Is there actually any noticeable difference in available power, engine ...
6
votes
1answer
264 views

How to know whether a Lexus rx450h qualifies for California Emissions standards?

I'm looking at a 2012 Lexus rx450h but will be moving to one of the states (Arizona, Connecticut, Maine, Maryland, Massachusetts, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, ...
5
votes
2answers
765 views

How is barometric pressure related to emissions testing?

In the VW emissions cheating scandal, news reports say the following: According to the EPA, "the position of the steering wheel, vehicle speed, the duration of the engine's operation, and barometric ...
5
votes
4answers
1k views

Emissions Problem: Lambda AND CO Slightly High on my 98 Mazda 626

I just took my 98 Mazda 626 for it's inspection and they said the carbon monoxide is slightly high. The test is done using a tail pipe gas analyzer while holding the RPMs between 2500 - 2800 for ...
5
votes
1answer
3k views

What is the purpose of secondary air injection?

What is the purpose of secondary air injection in a gasoline engine? It seems to be an old technology, according to Wikipedia it was introduced in 1966. Does secondary air injection have any value in ...
5
votes
1answer
129 views

Relation of VIN of a car with emission norms of a country it is sold

A VIN of a car determines the country of manufacture. So if a car has a VIN of Canada (CARB emission standard) and is sold in India (BS-IV emission standard), will the car comply with BS-IV standards? ...
5
votes
1answer
12k views

How to determine if P0430 is O2 or catalytic converter

2009 CTS4 3.6L P0430 catalyst below efficiency bank 2 comes on periodically. (There are no other codes being thrown.) I put a data logger on it today on my drive to work and the rear sensor is ...
5
votes
1answer
600 views

2003 Toyota Rav4 ECT Too Low for Readiness Monitor Drive Pattern

I recently failed an emissions test because my CAT and EVAP readiness monitors were "Not Ready" following a reset check engine light a few weeks back, which told me that the engine coolant wasn't ...
5
votes
1answer
4k views

Passing Emissions Test: Can't figure out how to fix code P0705 on a 1997 Nissan D21 / Hardbody / Pickup

So hello. I have had a lot of luck with my other vehicles on forums and a recently became the (hopefully-soon-to-be)-proud owner of a 1997 Nissan D21/Hardbody/Pickup XE. It has 156k miles on it and is ...
5
votes
1answer
507 views

Ibiza Mk2 MOT emissions test failure

I've had my SEAT Ibiza Mk2 for about three years and it's just failed its MOT on the emissions test - there's fuel in the exhaust on idle, and only on idle. It's in the garage at the moment and they'...
5
votes
0answers
615 views

Evap. circuit malfunction on Mercedes Benz

I have a 2002 ML320 suv. The CEL is on, and the code is P0446. It states that there is something wrong with the evap. system circuit, specifically at the charcoal canister shut-off valve. I've tried ...
4
votes
4answers
23k views

Best Ways to Pass Emissions?

I recently bought a 1989 Mercedes 300E that didn't run. Has a straight-six gas engine. Thanks to the miracle of Seafoam and a lot of luck, I was able to get fuel delivery happening again. I then ...
4
votes
2answers
4k views

How to install a California oxygen sensor into a federal catalytic converter assembly?

I have a 2000 Mitsubishi Galant ES 2.4L Engine with California emissions. Installed is a new federal catalytic converter assembly. The problem is that I do not know what kind of oxygen sensor to ...
4
votes
2answers
6k views

Will eliminating factory catalytic converter have effect on emission testing?

I'm not exactly a car guy or know much about cars, but I would love to get some performance headers installed. The problem is that the headers that I found for my car state the following "Eliminates ...
4
votes
5answers
6k views

2011 Chevrolet Cruze - Clicking Noise When Braking

So I leased a 2011 Chevrolet Cruze, brand new (only 2 miles on it), last November, 2010. It was running perfectly fine for a while. Brought it in for the standard tire rotation/oil change a few months ...
4
votes
2answers
246 views

What are vehicle emission limitations in Bavaria? [closed]

I currently work in USA but I'm going to relocate to Münich, Bavaria. The thing is I want to transport my 2001 Ford Mustang to Germany. My only concern (other than costs of course) is that European ...
4
votes
1answer
210 views

Possible Fuel pump damage

My Toyota Vitz 2007 idles very rough. Sometimes it stalls if I suddenly stop after few miles drive. I took the vehicle to a mechanic and he cleaned up the fuel pump. He used compressed air to clean ...
4
votes
2answers
2k views

Is a secondary air injection pump motor necessary?

My check engine light came on and the mechanic said the problem is that the secondary air injection pump motor broke. It's a used car (2004 VW new beetle) with about 150,000 miles on it and the parts ...
4
votes
1answer
105 views

Exhaust on a replaced motor

I recently had to change the motor in my 2004 Hyundai Sonata. I bought a used one from the junkyard, and it fired right up after I got it put in, and all the wires, hoses, etc. connected. The only ...
4
votes
2answers
2k views

2000 Nissan Maxima Service engine light

The dealer diagnosed it and says it got tripped by catalytic converter and rear oxygen sensor. The total estimate was around $2000. The blue book value on his car is around that amount. Is there a way ...
4
votes
1answer
53 views

Smog test fail, lack of oil?

I have a 2001 Toyota Corolla. It failed a smog test and it misfires. It has a code that the vehicle repair shop doesn't recognize, could this be because of lack of oil in my car? My stepson has never ...
4
votes
1answer
619 views

How to calculate fuel consumption and CO2 emission on flex fuel cars using OBDII data?

Here is the thing: I'm trying to estimate the fuel consumption of cars using OBDII data. It's quite simple if we can treat each fuel and its stoichiometric air fuel ratio separately, but when it turns ...
4
votes
1answer
1k views

Which O2 sensor is bad?

I'm getting codes p0031 and p1148 on my 2007 Altima 3.5 SE. From what I've read, p1148 is caused by p0031. P0031 relates to the voltage on the heater circuit of the 02 sensor on Bank 1, Sensor 1. I ...
4
votes
4answers
114 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 ...
4
votes
1answer
175 views

Won't pass emissions, Bad ECU?

So, Last year my 94 Acura Integra AT passed emissions by the skin of its teeth, this year it won't pass, I have noticed in past year and half that dropped from around 30mpg to about 15mpg. Some times ...
4
votes
1answer
708 views

Effect of smoke ingestion on fuel injected car engine?

My father asks, can smoke in the air from wild fires cause a fuel injected engine to choke? (He seems to think this was once true for carbureted engines - was it?) My personal guess is that we can ...
4
votes
1answer
1k views

Would an ethanol engine require a catalytic converter?

Would an engine designed for 100% ethanol require a catalytic converter? From what I've read ethanol creates little to no carbon monoxide or hydrocarbons, and very low amounts of NOx. Not sure how ...
4
votes
1answer
76 views

1993 Ford Taurus LX 3.0 Catalytic Converter

I've failed my smog test 3 times in a row within a week. They told me it was the EGR. So I changed my EGR Valve, EGR Solenoid, and my EGR Pressure sensor. The vacuum lines running from the EGR Valve ...
4
votes
2answers
482 views

Evaporator canister purge system advice needed

1995 Blazer - 4.3 L Vortec V6 CMFI (vin W w/ PCM) 230,000 miles There are no trouble codes. This is a OBD-I or 1.5 system from a GM transitional year (I have the OBD-II style connector). I have ...
4
votes
0answers
1k views

High CO Emissions

My Yaris is due for an MOT this month. The last MOT report says that CO is right on the limit, everything else is normal HC, Lambda etc., as shown below. The CO has been creeping up every year, and ...
4
votes
0answers
69 views

Results surprising said lab reporter of emission testing on Toyota Qualis Diesel 4 wheeler on AVL DiTest MDS 205

I got emissions of Toyota Qualis Diesel car tested with the AVL DiTest MDS 205, the result sheet had following columns rpm, temp, secs, CO(%vol.), CO corrected, CO2(% vol.), HC(ppm),HC corrected(ppm),...
3
votes
2answers
635 views

What fuel injectors I have to install? [duplicate]

Recently the fuel injectors of my Mazda 3 SP5 2006 2.3L stop working, they still works, but my mechanic said that are in bad conditions. Anyway, when I search the fuel injectors for my car, I found ...
3
votes
3answers
12k views

Failed inspection on because of OBD2 readiness

My 2008 Hyundai failed inspection because the OBD-II system is in a "not ready" state. The mechanic asked if my battery had died recently. It had, after getting an alignment. He suggested driving on ...
3
votes
2answers
22k views

Failed emissions - high lambda, low HC and CO

My 2007 Daihatsu has failed the national car test on emissions. The readings at 3500rpm are: Lambda: 1.10 (normal range 0.97 - 1.03) CO: 0.02% volume (normal range below 0.20%) HC: 11ppm (normal ...
3
votes
3answers
5k views

Will a universal catalytic converter set off the check engine light on an Infiniti G35?

I have a 2004 Infiniti G35 and the bank 2 catalytic converter has triggered the check engine light. If I replace it with a universal Magnaflow catalytic converter (approximately $100) will the check ...
3
votes
2answers
377 views

Access to EVAP Canister Vent Valve

My TSX is coding P2422 - EVAP Canister Shut Valve close malfunction. I'm finding posts online that it is often a blockage (spider nest??) that can be blown out with air. I'd like to try that first ...
3
votes
1answer
796 views

Car loses power while driving very briefly and on hills?

At this point I am positive it has something to do with the exhaust system but I am hoping to narrow down whether its a bad sensor or a gasket issue. I will replace them all but kind of enjoying the ...
3
votes
1answer
7k views

Very high short term fuel trim

I was checking my short term fuel trim numbers and o2 sensor switching speed as I think my post-cat sensor has degraded. The car is not throwing a code, and I don't believe that there's a hole in the ...