sal826

Well it finally happened - she failed smog for the first time in her life at only 35K miles. I guess according to the guy the NO number was at 560and California just lowered the fail mark down to 500 - so it failed.


Now what - there is absolutely no way I can fix this!

carter200

This is one of the reasons I left California and will NEVER move back......Get out while you can!!!

mike100

Z51 jeff put in new O2 sensors and his cleaned up enough to get the NOx down. They keep lowering the standards every few months...I would assume they will just bring them to zero at this rate.

Another guy got an exemption from a referee to build his own pipes with aftermarket cats.

Also; You were selling that car last year weren't you?

sal826

I just cannot believe this incredible freakin BS crap. The car's NO levels are exactly where they were last smog, but NOW it fails. I have heard of people changing the o2 sensors, but to be honest I havent a clue where they are located. Also, I've heard of others saying to put 1/3 tank ethanol - but that scares me. LAstly, some have said they replaced the CAT's, but I just cannot see myself doing that with a 35k mile car.

And, yes I was selling it, but people that look at these cars are extremely strange and tend to love to make lowball offers sight unseen (which I will not go for).


Sal

VetteMed

O2 sensors are in the exhaust manifolds. Have to remove from underneath the car.

8388

Did you get the engine nice and hot?

When was the last oil change?

Also, there are additives that guarantee to lower emissions. Never used any but some people swear by them.

LT5corsa

Did you reinstall your stock chip?



David

mike100

The whole point being made is that the car is putting out about the same emissions it has for 10 years +, it is just the state is lowering the pass/fail standard to squeeze older cars off the road before their time.

sal826

Never had anything but the stock chip. I guess I'll try burning out all the older gas, change the o2 sensors and put in fresh oil. Honestly if this doesnt work I'm screwed with this car.

ZR-71

Make sure whenever you go for the test to do a pre-test without connecting to the state's computer

WICKEDFRC

That is BS. if it passed before and they lowered the standard, there should be some sort of "Grandfather" clause if it has not gone ABOVE what your LAST inspection read. Meaning, it can go lower to newer compliance, but certainly not OVER what your last reading was.

What horsecrap. I love the scenery, beaches, and overall lifestyle of CA but I would NEVER live there for these midevil rules in today's modern society.

When I last visited, my buddy warned me not to even rev my engine while cruising somewhere along PCH. He said "Around here, they will ticket you just because of how loud it is, so don't draw any attention" Even suggested I stay below 2000 rpms. What kind of **** is that? Some motorcycles make more noise than that stock!!

VetteMed

CA = liberalism run amok.

bdw18_123

Also, you want to make sure you get your cats good and hot before the test, so drive around a bit and get the RPM's up there. If they aren't hot, you won't do well on the test.

Coupe89

Was 560 at 15 mph or 25 mph?
My results are posted on the zr1.net.

Time for longtube headers and new cats...

sal826

My "NO" number was about 580 - all other measurments were in new car spec territory according to the tech.

sal826

Thats interesting because I hear others saying you can fail the NO test because the engine is running too hot.

mike100

TRUE (for NOx)

The best I can figure is that new cars benefit from faster, more precise computers that keep the air/fuel in EXACTLY the right ratio to keep NOx down without going rich and elevating the other figures (HC/CO). Lean makes the combustion temp a little higher.

The newer catalysts also seem to have a larger percentage of the substrate dedicated to scrubbing NOx...plus I think they build in more cam overlap and EGR function to keep combustion temps at low speeds down on newer engines.

The early LT5 is SOL on all of these accounts (slow ecm, high compression without EGR, and early design 3-way catalysts). Once they wear out the NOx part of the 3-way catalyst, you can't make it really run too much cleaner. Lord knows they burn a little oil and this coats down some of the good catalyst metals in the substrate.

The only thing you can control is ign timing (which directly affects combustion temp) and putting in the very newest oem O2 sensor which might help find lambda more accurately. I have been curious to try a custom chip with 1 degree less timing at the lower rpm ranges the test is conducted in.

zr1don

Turn both your electric fans on early (10 deg lower than stock) and take out 2 deg of timing advance in the testing rpm range. This will lower NOX slightly. It looked like you were cleso to passing w/everything stock, this should get you through the test. New O2 sensors will help too.

RKC

I have the same problem with high NOX emissions here in CA. I was right on the edge last time so I doubt I would pass now. I had brand new Cats with SW headers, plug, oil, new stock chip, new radiator and barely passed. I've considered removing the resonator and replacing it with a third catalytic converter for smog testing. It might take a bit to heat up that third converter, but I read another post where someone had multiple converters on (maybe 5) and it worked to get it past smog. It should be a relatively inexpensive test to see if it works. Biggest problem would be finding a suitable converter and welding on two 2 1/2" in/out pipes. It's unlikely the smog technicians would know or complain of an additional converter. Just a thought, because it won't get any easier here in the future.

HAWAIIZR-1

On the bright side, you have a better chance at passing in CA than I do here in Japan. One year later and 4 years to go; I'm sure I'll never pass. Good luck to you.