please help me pass smog!

[Randall]

Hello all,
long time since I've been on the forum!!
still in love with my SHO!

Anyway, I have been trying to get my SHO to pass smog here in San Jose California, and it keeps failing on the NO, Nitrous Oxide, side of things, having doubled the allowed amount. The other two categories, CO and HC, it actually is well below the normal amounts and passes with ease on those.

Here is the backstory, I usually run a catless SHOShop Y-pipe, and when smog time comes around, I run an old catted stock y-pipe which usually gets me through the first try. Now, I have a 3.2 in there for the first time, and I may have mixed up a bad O2 sensor in the equation during the y-pipe swap as well. I know with my 3.0 and 3.2, there is a very intermittent misfire that can only be heard at idle and comes and goes sometimes not happening for months, but I have suspected a vacuum leak for a while. To cut to the chase, I installed the stock y-pipe, checked for vacuum leaks, and tightened all exhaust ****** bolts, and the car failed.

When I got home from the 2nd failed test, I got codes 116, 136, and 176. I know that the 116 was probably because the engine was not warm enough, and it and code 136 didn't come back when the engine was warm later on. The 176 is still there, even after I swapped a used O2 sensor in, and it looks like the front and the back sensor connectors are different so I can't use one of them!

So, there it is, if anyone could lend some tips that may help me pass, I would be extremely appreciative as my plates are now expired and I do not enjoy dodging highway patrol to avoid a twenty minute question and answer session, lol!

I do have a second stock y-pipe that I could swap in that did pass me 4 years ago as well.....

Thanks so much for any help!
-Randall

 

[ctwrench]

Pull the spout connector.

http://www.shoforum.com/showthread.php?t=56278&highlight=spout+connector

 

[itwonder]

Try a forum search of the word SPOUT. That will find a lot of past posts that will help you.

 

[sperold]

I think some O2 sensors are heated and have 3 wires (manual transmission) and other 02 sensors are not heated with 2 wires (automatic transmission). But on the same car, you can't have 2 different types of connectors. Solve that problem first.
Do the spout pull as advised above. It should get you through the test if you don't miss by much.
My car failed with the spout pulled and a total tune up..... it was the cats themselves.
Go to a shop or borrow a heat gun (sensor) that measures temperature by shining a pencil beam on the surface you are interested in. The cats should be about 600 degrees F at both ends. If not, that is your problem.

 

[Randall]

Thanks Eddie, Bob, and sperold! I will definitely try pulling the Spout when I go back on Friday, I have also been seeing the check engine light come on today for the first time in years, and I pulled a code 136, and when I did the KOEO test I got a 176. I know the technician at the shop I go to for smogs actually checks for the Spout being connected, so I am making a dummy one with the two pins inside broken off so it will pass his visual inspection! I got to say though, having the cats back on the car is kind of nice, it is no where near as loud, but it has that cool exhaust tone and it no longer smells like raw gas when I have the windows down and pull up to a light, lol! Maybe I will keep it legal from now on!
Thanks again guys, your input so far is appreciated!! I will do a search for the 136 and the 176 together, but so far I didn't see anything other than the front O2 sensor being on it's way out.
-Randall

 

[rubydist]

high NOx is almost always due to a lean condition. this could be due to a bad O2 sensor, but doesn't have to be.

I had a 3.2 a while back that would run warmer than it should and would not pass emissions. It turns out the prior owner had the timing belt off a couple teeth on the rear bank, and that valve timing was screwing up the emissions. once I corrected the valve timing, it passed first time.

 

[Randall]

So, I found out that the front O2 sensor was unplugged somehow, so I reconnected it, drove the car on the freeway for 10 minutes and then installed a dummy SPOUT connector right before going in to get the third smog, and here are the unbelievable results:

first test I had:
288 and 269 HC's, .56 and .61 on the CO's, and 1660 and 1355 on the NO's
second test I had:
23 and 15 on the HC's, .08 and .04 on the CO's, and 971 and 862 on the NO's
third test I had:
27 and 15 on the HC's, .05 and .14 on the CO's, and 89 and 101 on the NO's!!!

Pulling the SPOUT makes a huge difference, I never needed to do it before, but the smog tech said my emissions were similar to that of a new car!

Here's one more strong vote for pulling the SPOUT prior to getting the smog test done on a SHO. On mine, I just got a spare SPOUT connector and pulled out the two pins inside with some needle nose pliers and installed that, so that when the tech checked it, it would look legit!

Thanks for all the replys!