WTF? My car failed smog check :( *UPDATE*

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bolido2000

Diamond Member
Dec 3, 2001
3,720
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I don't understand why. My car failed the NO test. I took it to the mechanic and he said he couldn't finish cleaning the EGR valve in one day. Why does that valve get clogged?? Is this normal? I'm wondering if my car had a odemeter rollback now :(

UPDATE: Ok, so now the mechanic tells me that everything *should* be fixed. However, he says I need to drive the car for 3-4 complete cycles to reset the onboard computers. He said he already drove my car for 20 miles :frown:, but the levels are still not going down or something. sigh...I guess I'll pick the car up and go back on a few days to do the smog check. Oh yeah..by cycle he meant driving the car slow, fast, accelerating and then shutting down the engine.
 
The Stigenator

The Stigenator

Lifer
Oct 9, 1999
15,216
3
81
did you get a tune up..

NOx = incomplete burn..

My smog test had HC as high (around average of what's its supposed to be), but that was because of fuel injector cleaner i put in 2 tanks before.. otherwise NOx and CO2 and even CO were exteremly low..

I got 65K+ on my focus.. however a tune up and bad timing can affect burning.. i had a friend get bad smog results, a day of work on his car and it passed in flying colors. Yes we cleaned out his EGR valve... we did it all at home. It was maybe about 90 bucks in parts cost. Most was a new airfilter, new plugs, new cables, new distributor and a timing check. We ofcourse went ahead and did a compression check which it passed. His timing was a bit off.. along with his idle.. once we fixed that.. it passed no problems.
 
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acemcmac

Lifer
Mar 31, 2003
13,712
1
0
Originally posted by: The_good_guy
did you get a tune up..

NOx = incomplete burn..

My smog test had HC as high (around average of what's its supposed to be), but that was because of fuel injector cleaner i put in 2 tanks before.. otherwise NOx and CO2 and even CO were exteremly low..

I got 65K+ on my focus.. however a tune up and bad timing can affect burning.. i had a friend get bad smog results, a day of work on his car and it passed in flying colors. Yes we cleaned out his EGR valve... we did it all at home. It was maybe about 90 bucks in parts cost. Most was a new airfilter, new plugs, new cables, new distributor and a timing check. We ofcourse went ahead and did a compression check which it passed. His timing was a bit off.. along with his idle.. once we fixed that.. it passed no problems.
Click to expand...

sounds like fun. I wanna try :beer:
 
K

Kelvrick

Lifer
Feb 14, 2001
18,422
5
81
My 93 camry didn't pass and I was pissed. You must be even angrier. Ended up being a lose hose somewhere. I probably knocked it loose myself while replacing my radiator.
 
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Wingznut

Elite Member
Dec 28, 1999
16,968
2
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Originally posted by: The_good_guy
did you get a tune up..

NOx = incomplete burn..
Click to expand...
Actually, CO (Carbon Monoxide) is a result of incompletely burned hydrocarbons. NOx (Nitrogen Oxide) is a result of cylinder temps too hot, or inefficient catalytic converter.

The EGR Valve (Exhaust Gas Recirculation) does exactly what it says it does... Recirculates exhaust gasses back into the combustion chamber. Exhaust gasses are (obviously) inert and since they take up space in the combustion chamber, this reduces the combustion chamber temperature.

A plugged EGR system is really not unusual for 93,000 miles.
 
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petejk

Senior member
Apr 6, 2002
463
0
0
my egr value is dirty ...i drive a 1998 toyota camry.

I have this book from pep boys....but i cannot find an image of the egr valve...

I know that it sits close to the throttle body....anyone have any pics of an egr value...or how to clean it?
 
The Stigenator

The Stigenator

Lifer
Oct 9, 1999
15,216
3
81
Originally posted by: Wingznut
Originally posted by: The_good_guy
did you get a tune up..

NOx = incomplete burn..
Click to expand...
Actually, CO (Carbon Monoxide) is a result of incompletely burned hydrocarbons. NOx (Nitrogen Oxide) is a result of cylinder temps too hot, or inefficient catalytic converter.

The EGR Valve (Exhaust Gas Recirculation) does exactly what it says it does... Recirculates exhaust gasses back into the combustion chamber. Exhaust gasses are (obviously) inert and since they take up space in the combustion chamber, this reduces the combustion chamber temperature.

A plugged EGR system is really not unusual for 93,000 miles.
Click to expand...

I was told that NOx was also due to incomplete burn.. may not be as much as CO based which is definately incomplete burn. EGR does recirculate the gases, but i dont know how it actually reduces the amount of NOx.. cause NOx isnt combustible.. other than lowering tempratures it shoudlnt be doing much more than that.

EGR cleaning was once posted by someone.. roger or quixfire at some point.. search the archives..
 
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Wingznut

Elite Member
Dec 28, 1999
16,968
2
0
Originally posted by: petejk
my egr value is dirty ...i drive a 1998 toyota camry.

I have this book from pep boys....but i cannot find an image of the egr valve...

I know that it sits close to the throttle body....anyone have any pics of an egr value...or how to clean it?
Click to expand...
I don't recall the Toyota offhand, but it will be bolted to the intake plenum (but not necessarily right next to the throttle body).

Typical EGR valve pic... Take note that's not a Toyota EGR valve. But yours will look similar.

How to clean it? Remove it and clean it. Most likely, the passages in the intake will be clogged, which is what will really need cleaning. Sometimes they are pretty easy, sometimes they are a real bear. Be sure to have a new gasket on hand, as you'll need to replace it. Also, be sure to clean off all of the old gasket material from both the intake manifold and EGR valve itself.
 
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Cashmoney995

Senior member
Jul 12, 2002
695
0
0
It could be your 02 (oxygen) sensor which is gone bad

I had a 93 camry which pretty much same thing happened. Seems like that happened to be the case with a lotta peoples camry, people here got the 4 cylinder right?
 
Kadarin

Kadarin

Lifer
Nov 23, 2001
44,296
16
81
My (just picked it up yesterday and registered it today) 1990 Accord EX just passed smog.. ;) The guy said he had to warm up the catalytic converter for a while first, however...
 
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Eli

Super Moderator | Elite Member
Oct 9, 1999
50,419
8
81
An oil change and a tuneup could clear it right up.

How far off Pass was it?
 

Wingznut is absolutely correct, oxides of nitrogen are caused by high combustion chamber temperatures, these high temps break down the normally inert nitrogen found in the air.

EGR valves plug up because you are burning HYDROCARBON fuel in your engine (ever notice the black soot at the end of your tail pipe?)
 
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IamElectro

Golden Member
Jul 15, 2003
1,470
0
76
Originally posted by: Roger
Wingznut is absolutely correct, oxides of nitrogen are caused by high combustion chamber temperatures, these high temps break down the normally inert nitrogen found in the air.

EGR valves plug up because you are burning HYDROCARBON fuel in your engine (ever notice the black soot at the end of your tail pipe?)
Click to expand...

^^^What they said. You will probably notice a little better fuel economy after its cleaned as well.
 

Oh, I forgot to mention, if your mechanic cannot clean a EGR valve in one day, he should go back to bagging groceries.
 
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bolido2000

Diamond Member
Dec 3, 2001
3,720
1
0
Originally posted by: Roger
Oh, I forgot to mention, if your mechanic cannot clean a EGR valve in one day, he should go back to bagging groceries.
Click to expand...

I'm starting to feel that way too, although maybe there was another problem besides the EGR.

The max NO is 430. My car got 470. Still very high considering that the average is around 15. I drove the car for around 1 hour before doing the test
 
StageLeft

StageLeft

No Lifer
Sep 29, 2000
70,150
5
0
Your max is fine. Easy fix, I'm sure - it's common knowledge that manufacturers of high performance vehicles often have problems meeting emmisions. This is why a lot of foreign exotics are often difficult to import. :D
 
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Wingznut

Elite Member
Dec 28, 1999
16,968
2
0
Originally posted by: Roger
Oh, I forgot to mention, if your mechanic cannot clean a EGR valve in one day, he should go back to bagging groceries.
Click to expand...
Maybe the mechanic meant that he was too busy to get it completed that particular day.

But otherwise, you are correct. Even if you had to r/r the intake manifold... That's still only a couple hour job.
 
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kroq

Senior member
Dec 10, 2000
229
0
0
I have a 99 Mitsubishi Galant with only 70k that didn't pass last year and I bought the car new, no accident, not even incidents. Ended up the data output device that gives the RPM read out to the smog station failed. Now that's a WTF.
 
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TheNinja

Lifer
Jan 22, 2003
12,207
1
0
Put in a new air filter. My buddy's older car failed recently, he put in a new air filter and it passed.
 
NutBucket

NutBucket

Lifer
Aug 30, 2000
27,153
635
126
Originally posted by: Astaroth33
My (just picked it up yesterday and registered it today) 1990 Accord EX just passed smog.. ;) The guy said he had to warm up the catalytic converter for a while first, however...
Click to expand...

Uhm, you have to get the cat hot period. My 91 was still passing with flying colors last year. Not so sure how it'll do next time around;)
 
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