Failed Again

[sperold]

Went for the Emission Test and it failed (on my 95). Don't have the numbers right here with me as it is being done 120 miles from here. But I will get them up as soon as I can (with Christmas and all).
But here is the thing........
Last time I went (2-years ago), I installed the SHOSource equal lenght sytem on the car and it passed. Since then, the car has not gone over 2K.
I had the diagnostic done on it at the Test Station by a guy who I believe to be trustworthy and the report was that everything is within range, all sytems are operating efficiently, but it needs Cats as the Nox is not being delt-with.
Now, when I got the system from ShoSource, I filled out a lot of paperwork with the cats and sent it in. But is it really the cats? Or should I wait and see. Even though I trust this place, it still sounds fishy to me that something would fail so soon.
Any thoughts?

 

[Phoenix]

Allthough we dont e-test here , from what I have heard , new O2s will do wonders. But I dont know if it fixes the NOX....

 

[SHOtimer]

Pull the spout.

Doug

 

[ShadetreeSHOguy]

Pull the spout. If the cats went bad that quickly id suspect you're getting some sort of blow-by of some sort burning up the catalyst material. So it very well could be true.

 

[sperold]

Yea, I wasn't there to do that little ceremony, and I don't think the testing facility will do that for you... as they would consider that a cheap trick.
Like I said, I don't know how much it failed by, but the numbers are so small they defy description anyways. Part per million my a.. . I would have thought you would have to be in a laboratory to get numbers like that.
Anyways, just part of my 2 year ritual that is just about driving me crazy because with 4 cars, I am doing 2 per year.
I got a conditional pass so I am good for 2 more years, and that will be plenty of time to try stuff like new O2s.
Am I right in thinking the warranty on the cats is not worth persuing?

 

[Ishodu]

You pull the spout before you get there or before you leave the car with them. They will never know. There is instructions in the How do I section. It will likely pass then.

 

[rubydist]

The only time I had problems with failing emissions due to high nox, was when the rear cam was out of time by a couple of teeth.

the car also tended to run toward the hot side - that was really the only symptom I noticed prior to the emissions issue coming up.

I suggest you double-check the cam timing.

 

[msteiny]

The only time I had problems with failing emissions due to high nox, was when the rear cam was out of time by a couple of teeth.

the car also tended to run toward the hot side - that was really the only symptom I noticed prior to the emissions issue coming up.

I suggest you double-check the cam timing.

A couple teeth? How did it run?

 

[Frisbeeguy]

My '89 also failed within a few thousand miles with a new ShoSource equal length Y pipe and new O2 sensors. Pulling the spout made it pass easily.

 

[rubydist]

it was a little down on power but not so much that I knew something was wrong - I just thought the engine was tired.

because it failed emissions, I decided to do all the 60k work to see if that would fix it or if I needed to tear the heads off, and I discovered the cams were out of time. the timing belt was not that old, so whoever had done the work just didn't pay enough attention to getting it all lined up when they installed it.

 

[sperold]

Thanks for the heads-up frisbeeguy. It is nice to know I am not alone. If I would have been there, I would have pulled the spout, and things may have been different.
Maybe the "high flow" models don't have enough time to do a good job at cleaning up the exhaust. I am still miffed that their million dollar machine says everything is within spec, yet it failed.
When I am totally beat, I have a set of "california" converters (bought on this forum as a lark, but now I am glad I did) that I can swap on for a day, they probably are not too "high-flow". They probably stop the exhaust and scrub it with a brush.
The rediculous part is I had an 89 up until lately, that always went through the e-test and as far as I know, had the original cats.
Things that make you go "Hmmmmmm".
I will post my numbers when I get the test sheet.

 

[BaySHO Performance]

Pulling the SPOUT will reduce NOx by a factor of ten, so don't take it back to the same place or they'll smell a rat.

My NOx failure boilerplate:

NOx is formed inside the combustion chamber when excessive heat is present, usually because the engine is running lean. New O2 sensors typically don't help as old ones make the engine run rich, not lean.

A list of common causes of NOx related smog check failure:

1.Check the EGR system.This system is designed to reduce NOx. It consists of an EGR valve, PFE Sensor, EVR Solenoid and vacuum hoses. Its job is to reroute a
small amount of exhaust gas back into the engine to help reduce combustion chamber temperature. Not all vehicles have an EGR system. If yours is one of those, pull
the Shorting Plug (near the EEC Self Test) to reduce Nox significantly (factor of ten in my case).

2. Next thing to check is the air / fuel ratio. If the vehicle is running to lean, NOx emissions will increase.

4. Some possibilities are a restricted fuel filter, low fuel pressure, vacuum leaks, oxygen sensor, load sensor such as a MAP sensor, MAF.

5. Check the cooling system. An extra increase in water temperature will increase NOx production.

6. A defective catalytic converter can also increase NOx. The Cat reduces NOx that has already been produced.

7. I have a client who halved his NOx by cleaning all the crud out of the intake with Seafoam. The carbon buildup in the engine was raising compression and absorbing
the fuel mixture so combustion was running lean.

 

[msteiny]

Dead on, I vote for a sticky.

 

[rubydist]

yeah, on the car that had the cam timing problem, I pulled the spout connector and took it back, it passed easily and had plenty of power so they were none the wiser.

then I took the front covers off and discovered the cam timing issue.