Bombed emissions bad...

[biker889]

Took my car in for emissions today.
CO-1.29 HC-507 NOX-10,002

I Dont know where to start, everything has been replaced so its going to be even harder to narrow it down... any suggestions.
1994 3.0 mtx
magnaflow cats

 

[hawkeye18]

Step 1: Pull the SPOUT plug. Search the forum for "SPOUT" to find out where it is.

Step 2: If that doesn't work (and I don't think it will), replace your O2 sensors.

Step 3: If that doesn't work (still don't think it will), you'll have to replace your cats - they're fried.

Step 4: Torch the f***er, get a new SHO

 

[biker889]

I am leaning towards step 4....
really though, i have a stock y-pipe and 02's i will put on. i highly doubt the spout will help. my cats are only 6 months old, they better not be shot...If the timing belt was off one tooth could that contribute?

 

[Bob Gervais]

I am leaning towards step 4....
really though, i have a stock y-pipe and 02's i will put on. i highly doubt the spout will help. my cats are only 6 months old, they better not be shot...If the timing belt was off one tooth could that contribute?

Yes. Also scan it for codes, KOER, before you start throwing parts at it.

 

[biker889]

I have checked for codes....nothing came up

 

[Bob Gervais]

I'd go for timing then. A couple of years ago, I failed emissions badly with the 92/3.2 swap. Turns out I timed my own cams incorrectly when swapping the 3.0 cams into the 3.2.

Whoops....

 

[biker889]

I dont really think its a timing issue. i had replaced the belt, and i am pretty certain i had it on the correct line for the 3.0. because if i didnt, the marks are on pulley would not have lined up on the oil pump.

 

[Bob Gervais]

If the timing belt was off one tooth could that contribute?

You asked the question, which is why I gave the answer.

Other than that, I've got nothin'.

 

[Bob Gervais]

I dont really think its a timing issue. i had replaced the belt, and i am pretty certain i had it on the correct line for the 3.0. because if i didnt, the marks are on pulley would not have lined up on the oil pump.

I've had a long week, and a confusing day, so this may all be on me for misunderstanding...

In theory, you could have all of the pulleys lined up correctly, and still get the timing belt installed on the 3.2 mark. No?

 

[biker889]

I've had a long week, and a confusing day, so this may all be on me for misunderstanding...

In theory, you could have all of the pulleys lined up correctly, and still get the timing belt installed on the 3.2 mark. No?

Its how i phrased it.
We can just ignore that post...I am just rambling because i am frustrated. I am going to check my timing, verify no codes (again) and i will report back.

 

[Leo(209)(707)]

High NOX can mean high cylinder temps IIRC. I had high numbers like that, so i replaced O2 sensors and put new coolant in it. Then i disconnected the spout connector and i passed no prob. As far as CO and HC i have no clue what those are results of.

Good luck

 

[luigisho]

Even newer aftermarket cats are really inferior to the oem stuff. I love the cost of aftermarket replacements but in some models they throw emissions codes right out of the box.

 

[biker889]

No codes. Checked the timing and its spot on. I am gonna change my oil, swap ypipe and pull the spout

 

[luigisho]

That's about all the relatively easy fixes you can do and although the y pipe isn't that difficult, it is a PITA if it's cold or raining all the time this time of year.

 

[jedhead]

Removing the SPOUT will lower the NOX, but the HC will rise slightly.

Bob

 

[biker889]

Has anyone ever seen nox levels that high before? Last year the car passed with flying colors with the stock y-pipe....I couldnt imagine changing the y-pipe changing it that much....

 

[luigisho]

You're about to find out... report back what you find.

 

[Leo(209)(707)]

I had NOX that high when i first got my SHO. I had a brand new sho-source y-pipe with magnaflow high flow cats too. New O2 sensors and radiator flush dropped the numbers a couple hundred, but not enough. Pulled the spout then it was good to go by a lot.(it was a cold day as well, that may have helped too)

 

[HotRodKid]

Its your converters. its not that their shot, its just that they didnt do anything when they were new. Performance converters are less restrictive, which allows more exhaust to pass through them without being "converted"

 

[hawkeye18]

They shouldn't be that unrestrictive.