I FAILED SMOG!!!!!! I have never failed with anything in my entire life let alone a SMOG test....I'm getting an ulcer. The bastards looked at everything in the car...they questioned the valve cover breather, MSD ignition, and looked under the car for a set of cats. Its strange that the other people who were there to get smogged didn't get much trouble from the techs.

The car has 71K on the clock with stock plugs & wires. The cats have about 50K on them and the oil is about 3K old with the air cleaner looking fairly clean. The results can be seen here http://www.geocities.com/blown383/smogtest I'm still trying to figure out how to blow up the pic so you can see it clearly. I failed the NO (PPM) portion of the test. On average the most cars would register 57 PPM of NO @15mph and 50 PPM of NO @ 25 mph. The maximum @ 15 mph is 419 PPM and my car measured 443!!!!!!!! At 25 mph the maximum is 706 and my car measured 554.

I borrowed a Granatelli MAF to use for the test because my stock one is dead. However i'm not sure if that MAF is calibrated for my car. (This maybe the reason why my car failed) What do you guys think?



-B

 

it probobly has something to do with the blown 383 under the hood


NOx is usually due to EGR failure (or even a lean condition i've heard- not 100% sure on that)

 

Don't have a blown383 yet.....its a stock LT1 with minor bolt ons.

-B

 

I almost fail myself a couple of months ago with a high Nox reading. Did you have the car run nice and hot, as leave it on and let the car idle this will keep the cat's nice a hot. Also find another shop and get another reading.

Vinny

 

Time to check your cats and egr!

Here are my numbers with 2 new flp converters and longtubes:
NO (PPM) @ 15 MPH: 113
NO (PPM) @ 25 MPH: 74

My EGR had been disabled a long time ago because I have the hotcam. This cam has enough valve overlap to create an EGR effect. This is why the '96 vette had no egr.

Most shops will gripe about a valve cover breather because it is technically illegal and really obvious. When you bring it in next time, take the breather off and go back to the stock configuration.

My theory is that if you are ever pulled over by the cops and they want to look under your hook, it better look good, ie like all the smog stuff is connected. I have heard a few stories of some mustang guys getting fined and or arrested big time for stuff like no cat converters, etc.

 

Huh... my '95 also BARELY passed NOx emissions... I'm *about to* put in a Hotcam, so this will actually HELP my NOx??

Thanks,

Michael

 

I don't think it would be the cats because they are only 50K old or less......how do I check the EGR? Before the test I had trouble code 154 and 160 which was insufficient activity on both O2 sensors on the passenger side. I cleared the codes and they never came back. Another thing I just remembered is that I have one broken manifold to y-pipe bolt and it's held on by 2 bolts and bunch of orange RTV.....so it leaks. Would that cause my NOx readings to go sky high?

-B

 

You have a few issues here. First, GM had recalls for the EGR valve, did you ever have yours replaced? I didn't bother, when it goes it's easy enough to replace. Pull yours off and make sure it's not plugged up with carbon, which is pretty common. Second, an exhaust leak allows oxygen into your exhaust stream, making the o2 sensors think you are lean when you aren't. Lastly, get some new oxygen sensors, sounds like yours have "hit the wall".

 

It will most likely lower your NO emissions. Just keep the stock programming and it should pass. You may have to up the idle speed a little. Keep the fans at stock temp. too.