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My emissions nightmare!!!

Edmond

Well-known member
Joined
Aug 1, 2001
Messages
5,218
Location
Louisiana
Corvette
2003 Z06
Okay, for the past 14 months, I just haven't been able to pass emissions here in IL. And my little sticker expired in Feb. so I haven't been able to drive my baby like I always do. I took it for a test today and had the following numbers:

Hydrocarbons 2.07 standard .80
Carbon Monoxide 28.4 standard 15.0

I've failed emissions 6 times in the past 14 months and it's really getting on my nerves. I'm planning on the following:

change plugs
change wires
change the front y-pipe because I think the little convertors are bad
I put in a new O2 sensor this week

catalytic convertor is only a year old
had the fuel system cleaned out a year ago
mufflers are a year old

Does anyone have any suggestions? I can't buy a sticker for my license plate and therefore can't drive until I can pass this emissions test nightmare!

What they do here in IL: 1981 and up, they put the car on a dyno and run it like that. 1980 and before, they do not use the dyno.
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Ouch

So when was the last time the plugs were changed? ( change cap & rotor too!and make sure you GAP the plugs properly!)

If you have Extra $$$ get a hot coil!

How does the car run?

No check engine light?

Are you loosing coolant....... and can't find the leak?

Is the car stored outside?

What fuel are you running?

When did you last change the air filter?

Did you verify the timing? ( and I'm wondering if your harmonic balancer slipped)

These L-98's are USUALLY a slam dunk when it comes to smog.

Mike
 

Edmond

Well-known member
Joined
Aug 1, 2001
Messages
5,218
Location
Louisiana
Corvette
2003 Z06
The car runs great, it accelerates fine and doesn't hesitate at all when I drive faster than the speed limit.

The plugs were done like 3 years ago so that might be a problem.

No check engine light.

I'm assuming that the coolant hasn't leaked. I don't see any of it in the driveway and for a period of time, it was parked there for 3 weeks without being driven.

I always use Amoco fuel usually premium but sometimes plus.

I have a K&N and I washed and recharged the filter a couple of months ago.

I did drive it for 25 minutes before I took it in for the test. It's a real pain because I have to drive 25 miles to Chicago to get this temporary sticker and that only gives me 5 days.
 

BigRed

Well-known member
Joined
May 23, 2001
Messages
948
Location
Edmonton
Corvette
1985 Bright Red Rocket
What about Modifications? Do you have aftermarket

Heads?
Mufflers?
Cats?

Are all your PCV and breathers clean?
Do you have a performance chip in it?
Do you have (Like Mike said) a Hot coil/and or Ignition setups?

Also (Out of my ballpark here) but on the pollution controls like the smog pump and I think the evaporator, Do these have anything to do with it?

If nothing else works stick some Condoms on the tailpipes:L
 
8

89ZZ4

Guest
Bullwinkle I'm sorry I got to this thread late. Before you change out your plugs get your tank down low and put 2-3 gals of racing fuel in and go for a nice ride to Joliet and back on 80. Run it down and then put in some good premium like AMOCO. It will clean out your system some if thats all there is. I passed with flying colors last November at the Joliet test station and that includes running a hypertech chip and a few minor mods. They let you ride with them especially with the 6 speed. If that doesn't work drop me a line and I can press my kid (Chev Tech at Phillips) to take a look see. I expect to pass emissions with my new set up without the pre-cats just using one large cat.

Phil (aka 89ZZ4)
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
You may be dealing with some very basic things. First, new plugs and wires will never hurt. Good quality AC delco plugs and wires will put you on track.

Second, I would suspect you have a failure in your air pump valves. If they are not pumping plenty of fresh air down into the cat, it will not burn clean. I hope when you had the CAT replaced that they replaced it with a stock style that has the AIR port on the side.

You also need to check all around the intake and the rubber tube that goes into the intake where the PCV is located. These get oil soaked and swell causing a vacuum leak that will make the car run rich.

Your charcol/evap canister may also be plugged full of vapor, and the tank may be purging right into the intake when you are testing it.

These items will kill you on an emissions test.

After you check them out, make sure the car is good and hot at the time of testing, and leave it running while in line at the inspection station.


Good luck!
 

Edmond

Well-known member
Joined
Aug 1, 2001
Messages
5,218
Location
Louisiana
Corvette
2003 Z06
Gentlemen,

I would just like to thank all of you for your vast knowledge and suggestions.

I think I'm going to do a tune up and a little general maintenance.

A tech from a few towns over told me to do the pup converters, which are 14 years old I might add. I'm thinking that I'll just do the plugs and wires first, see if it improves and then go from there. I'm in no rush to drive the car, especially since it snowed here today!, so I'm going to take my time doing things.

I'm just going to do little things and bring it back to test. It'll be a slow process of elimination, but it'll be good for my learning experience. I've never had so much fun and headaches in dealing with a car.:D
 

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