Emission Test

[lincolntran]

Hi,

I just bought my ls400 1990 with 94k miles. It just failed the emission test. I couldn't believe it.

why did it fail? How much will it cost for the repair?

Can someone help me out on this?

thanks

John

[tds]

Hi,

I just bought my ls400 1990 with 94k miles.  It just failed the emission test.  I couldn't believe it.

why did it fail?  How much will it cost for the repair?

Can someone help me out on this?

thanks

John

←

I suggest you do the following:

1. Try a second shop...the first one may have messed up the test or been fishing for business.

2. Make sure you take your car for a drive (60 mph for 10 minutes) before you drop it off for the emissions test...You've got to have your engine warmed up properly.

3. Use Sunoco 94 Octane (a full tank) before and during the test.

It is also possible that you have a bad oxygen sensor, or something else, but I would try 1, 2 and 3 first.

[SKperformance]

Actually TDS using the sunoco 94 before testing is fine but you don;t want to test with 94 as it will cause the car to run rich and cause even more emmisions and increase you HC (hydrocarbon ) readings.

What are your limits and readings for your test.

Without it their is no way to evaluate the test.

[wandawoods]

Hi,

I just bought my ls400 1990 with 94k miles.  It just failed the emission test.  I couldn't believe it.

why did it fail?  How much will it cost for the repair?

Can someone help me out on this?

thanks

John

←

my 98 ES300 with about 140K also failed the emmision test few month back, and a major tune-up corrected the problem. 94K is a good time to do a major tune-up (plugs/wires/ditributor caps+rotors/throtle cleaning..etc) anway....

[SRK]

If a shop tells you the engine failed the test, then they can tell you in what way the engine failed - high HC, or CO, or NOx. That would point the way to the correct repair to make it pass. Simple. No need to second guess this.

Whatever good quality gasoline you use will make no difference - the PCM will burn any gasoline properly - that's what a feedback system is for. When the emissions move out of the acceptable range it is because the PCM cannot trim the fuel curve correctly, or the convertors cannot deal with normal exhaust gases.

In any event, the shop shouldn't be looking for a blank check to fix this thing. They should be able to explain what failure is in terms of gases, and then explain which component(s) contribute to that failure. If they can't, find another shop.

[92Lex]

Hi,

I just bought my ls400 1990 with 94k miles.  It just failed the emission test.  I couldn't believe it.

why did it fail?  How much will it cost for the repair?

Can someone help me out on this?

thanks

John

←

Do you have the VIR printout they should of given you at the end of the test results? If you do then can you post the results on here....maybe I could give you an idea of what's wrong with your car (I'm a smog check tech).

Octane does matter when it comes to a smog check. If your car is designed to run on premium and you're actually running on 87 or 89...you might fail for elevated NOx.

[lincolntran]

Hi,

I just bought my ls400 1990 with 94k miles.  It just failed the emission test.  I couldn't believe it.

why did it fail?  How much will it cost for the repair?

Can someone help me out on this?

thanks

John

←

Do you have the VIR printout they should of given you at the end of the test results? If you do then can you post the results on here....maybe I could give you an idea of what's wrong with your car (I'm a smog check tech).

Octane does matter when it comes to a smog check. If your car is designed to run on premium and you're actually running on 87 or 89...you might fail for elevated NOx.

←

Hi, thanks for all the reply.

below is the result:

HC is 171 while allowable was only 130 --->this was failed

NOx was 1560 while allowable was only 905. --->this was failed.

rpm was 1245 and allowable was 2500

CO was 0.43 while allowable was 0.83

CO+CO2 was 14.5 while allowable was 6.0 min.

please help me out on this.

thanks alot.

[92Lex]

Are you using premium gasoline or regular? Were there any trouble codes? How about the funtional section of your test results...did everything pass, did anything fail? What were the results from your O2 readings?

If your O2 readings are well above 2% then I think you probally have a lean misfire there. Lean misfires (too much air and not enough fuel) are commonly caused by vacuum leaks, dirty injectors or low fuel pressure.

If your O2 reading is at or below 2% then maybe your EGR valve or catalytic converter has gone bad. I'm leaning more towards your EGR or catalytic converter because CO2 @ 14.5% is fairly normal (12.5% should be the minimum).

If possible, can you scan the bottom portion (functional test and emission results) so I can see?

[lincolntran]

I'll scan the entire emission paper in the early morning when I got to school.

thanks

[SKperformance]

Ls has dual exhausts?

Which one did they try ?

If one cat is gone then you might have bad luck.

I think it is more likely a cat as i just changed mine after a failed emmiosn test on my other car.

When was the

plugs

wires

rotor and cap

oil ( but it barely makes a difference to co)

changed ?

BTW hoew long did the car sit before the test?

Did the tech take it for a drive to warm up the cats?

[lincolntran]

Ls has dual exhausts?

Which one did they try ?

If one cat is gone then you might have bad luck.

I think it is more likely a cat as i just changed mine after a failed emmiosn test on my other car.

When was the

plugs

wires

rotor and cap

oil ( but it barely makes a difference to co)

changed ?

BTW hoew long did the car sit before the test?

Did the tech take it for a drive to warm up the cats?

←

here is the link to the emission result: http://www.htatlanta.org/images/emissionTestResult.pdf

thanks

[92Lex]

All those questions we've been asking you have EVERYTHING to do with test results.

Georgia doesn't show O2 test results? O2 + CO2 are real important to help us determine your air/fuel mixture...I'm surprise they would test for NOx but not O2. Anyways, it's probally the EGR valve or catalytic converter....like SKperformance, I'm too leaning towards the catalytic converter. The catalytic converter is usually the last thing a tech would check...have your EGR checked out first, then have a test and repair station do a catalytic converter efficiency test.

Your test failure probally doesn't have anything to do with fuel, even though you failed for elevated HC (unburned fuel). If fuel related then your CO should rise as well, and NOx should drop down real low because of the richer mixture.

Do you have receipts on what has been done to the car recently?

[lincolntran]

I don't have the receipt since I just got the car for only 1 week. I think I'm going to change all the fluid on the car and have the EGR valve and the catalic check out.

thanks

[92Lex]

I don't have the receipt since I just got the car for only 1 week.  I think I'm going to change all the fluid on the car and have the EGR valve and the catalic check out.

thanks

←

You should have a smog check and repair station do the diagnostic/repairs....that way they can guaranty you that it's gonna pass smog after repairs. Let us know how it works out.

[SKperformance]

Get a motorvac.

It helped mine ,i would have passed if it didn;t heat my cat so good it burnt the cat and blew out the back.

Damn cheap cat.

[gremio]

Reset your ECU before you go for testing!

[oversteer]

Lincolntran - I am also in GA and had almost identical results last week. HC was a little high but the NOx was way up there. I had the same problem last year and my mechanic cleaned the EGR system and got the NOx to pass by 1 point. This year I am WAY over at 2129 (905 to pass) and I am wondering if it is CATs. Can you tell me how your experience finally ended up?