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1990 T-Bird Smog question???

koolbz's Avatar

Join Date: Feb 2005
Posts: 40

03-26-05, 02:00 AM   #1  
1990 T-Bird Smog question???

I have a 1990 t-bird 3.8 v-6. I recently had the engine rebuilt
runs fine. However, I got a test only smog check test from dmv.
Since I have never had a problem with this car passing I was not
at all worried and just having it rebuilt further made me at ease.
I went for the test and was Floored when i was told it failed.
It passed all the usual tests but failed the NOX test.
Could someone tell me what I need to change in order to
get this Nox problem to come within limits so I can get it
registered. I cannot beleive it failed and am beside myself on what
to do. I would like to fix it myself but have never heard of this nox
Please can you help me
thank you

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hopkinsr2's Avatar

Join Date: Feb 2005
Posts: 1,561

03-26-05, 08:25 AM   #2  
Make sure the E.G.R. valve is hooked up & working. With the engine at idle, put a vacuum on the valve & the car should run rough or stall. Also check for vacuum on the hose with the engine warm & running 2-2500 rpm.

Daniel Wachtel's Avatar

Join Date: Nov 2002
Posts: 1,397

03-26-05, 05:19 PM   #3  
notorious for stuck EGR valves.

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