I bought a used vette about a month ago, apparently it was in rougher condition then I thought it was.

I failed the smog test again. When I first got the car I gave it a full tuneup etc before bringing it into get it tested.

the results of the first time:

HC allowed: 0.8000 Grams a mile
HC Result: 5.5510 Grams a mile

CO2 Allowed: 15.000
CO2 Result: 59.2111

left the emissions, tried to pull any codes off the obd interface. I didnt even get a code 12. So I pulled the dash apart, checked the bulb it was fine. I used the helms manual to diagnose it as a failed ECM. I replaced the ECM and the car seems to be running better, and I get the happy code 12, then the code 12 again. Since the computer said everything was fine, I brought it back to get it tested to see how it improved.

here are those results:

HC allowed: 0.8000 Grams a mile
HC Result: 3.0843 Grams a mile

CO2 Allowed: 15.000
CO2 Result: 54.3400

better, but still a failure. Here is what has been replaced so far.

Original Tune up:
Plugs, wires, cap, rotor, o2 sensor
It didnt want to start some times so I also changed the Coil, and Ignition module while I was in there.

A few days later I had a problem with the fan not kicking on, so I replaced the single wire, coolant fan temp switch on the passenger side, and the 2 wire temp switch on the top of the motor near the throttle bodies.

I have also changed the mufflers. (only because they were clogged with peices of the CAT). I know I need a new cat since chunks have broken off the old one, but I would like to fix the problem that caused the cats to fail, so I dont replace them and have the new ones go out in a year or two.

I have looked and looked, and I am unable to find a vaccum leak. Can I get some suggestions, or a point of where to look at?

Back to the helms manual, see you all in a bit.

 

tell us a little about the vette please... Like the YEAR

 

Odds are that it is a faulty EGR valve.
I had the same problem and once the valve was replaced, it passed.
Not saying that it is the EGR valve but it is a consideration.

 

oops sorry 1984 with the infamous crossfire engine. I did replace the EGR valve also, when i found a vaccum leak under it.

 

Sounds like you may have already fixed the problem that killed the cat (ECM)

If it’s running good and nor throwing codes go ahead and change the EGR and install a new cat.

You can find magna flow cats on ebay for around fifty dollars

 

hmm. I cant find the $50 one. Can some one suggest a cat that has good flow. I would prefer one with the flanges so I can bolt it on. I dont have a welder.

 

Ebay Cat Link

This is maganflows universal cat, and a muffler shop will need to install unless you want to go with a different front Y pipe.

 

SOMETHING YOU MAY WANT TO CHECK OUT: In Missouri if you bought the car from a dealer, they are responsible for giving you a "Passed Safety Emissions" certificate. Even if you bought the car from a private party "as is", Mo law says that the seller is responsible for furnishing the buyer with a "Passed" emissions certificate, i.e., "Private sellers of vehicles are required to provide the purchaser with a current emissions test approval or waiver for the vehicle prior to sale. The vehicle purchaser has 60 days from the date of the emissions test to use the certificate for registration" (MO revised statutes 643.315.1). To get the full text, go to www.gatewaycleanair.com/needtest/used.htm
The heading on the page will say "About Used Vehicles".

Also, as a last resort to get it licensed, check the "amount spent" requirement in order to apply for a waiver. I know this doesn't solve the emission problem on the car, but it "buys" a little more time for you to resolve it without the pressure.
Cheers

 

well i put in a new cat today. went and got the car retested.

HC allowed .8
results 1.2

co allowed 15
co results 19.0

They dropped ALOT, it almost passed so its doing better. then 2 problems arose...


1. I give them a stack of 600 worth or repairs ive done to the car, and they say only 300 applys for the waiver.

All i want to do is get some plates, so that I can buy some time to save up for the engine.

2. ever since they tested it, and it failed, they popped the hood, and started playing with the motor. I walked out to see what they were doing, and then they told me i had to wait in the room etc.... car started ok, but I got about 5 miles down the road and the car cut out and lost all power at once, it was simiar to a back fire but not quite. its done it a few times now. the check engine light came on after like the 5th time on the way home. I shut off the car and jumped A&B of the aldl and just got two code 12s. I start the car and the check engine light comes back on. It has never done this before so im aggraviated about this.

Thanks for letting me know about the law, im gonna call the dealership and see what they say.

 

Looks like the cat helped quite a bit. I would look at replacing the injectors if they’re original, check the fuel pressure, and synchronize the TB’s

Was the car/cat HOT when they tested the vette or did they let it sit in the parking lot for 30 minutes before they tested it?

Also, how many miles on the vette?

 

engine was hot. First time i have ever went to an emissions place, and didnt have to wait in line. the car has 163,000 and i know it needs valve seals. but i just bought the car, spent several hundered to get it this close to passing inspection. I still have to pay sales tax, and get the plates. So I dont have the money to do the valve seals now.

Still trying to figure out why it started wigging out after the test, yet i have driving close to a thousand miles or so since ive gotten it and never had that problem. Guess a clogged cat could of kept the problem from showing it self.

I have thought about replacing the injectors but i am also concidering converting it to TPI. I just want to get plates on it so that I can save my money, and make up my mind exactly what I want to do with it.

 

1. I would quit throwing money at it at this point.

2. Go to the website I referred you to. Print out a copy of the law and take it and the car and the "failed" sheet to the dealer. They are responsible for making sure the car will pass emissions.

3. If the emissions testing station made any adjustments or finagled with your car, I would raise holy hell. They are allowed to pop the hood to see if you made any modifications which would affect emissions but, to the best of my knowledge, they are not allowed to make any adjustments or diddle with your engine.

4. At the time of testing did you have a "check engine" light? You said you get the light now. Jump the ALDL, turn ignition on but don't start. You should hear your fan come on. The light will then blink a code 12, twice and then blink any problem codes (twice). After all problem codes are blinked, code 12 will blink twice again and the sequence will start over, until you turn the key off. Post any problem codes you get.

I've been told that an oil change before testing helps but I've also been told that even if you burn a slight amount of oil, i.e., valve guide seals, etc., that shouldn't really affect the test.

Are you in the St. L area?

Good luck.

 

The TPI swap would be a nice upgrade. Have you researched what its going to take? From what ive read it’s pretty involved, but I think the benefits over the crossfire would be worth it.

The guys may have been playing with the timing to get it that close, that and the TPS are the only things I can think of that they would have been trying to adjust to get it to pass.

Pull the battery cable and reset the computer, then drive it and see if the light comes back on.

 

looked under the hood, and foudn a wire laying on the exhaust manifold. spliced in a new wire. check engine light went off. When to the dealership, showed them the paper that said they were responsible. The manager hopped in the car with me, we went to get it tested. and it passed. dropped the manager off, and he even gave me some of the cash back. I have a street legal project car. I think it was worth the effort. so now i am just goign to troll the message board, till im ready to replace the gaskets that are leaking a little, get my heads worked on , replace the intake, get a paint job, and call it good.

Sorry for all the aggravation guys.

 

My error on previous post re error codes..code 12 will flash 3 times and then any trouble codes will flash 3 times each.

 

A few suggestions.

Have you checked your timing?

Also, you didn't say anything about NOx. If NOx not an issue, crank up up the timing, for it will help reduce the HC and CO.

Plus throw in some Methanol into the fuel.

Or move to Alabama . . .

 

Missouri smog???? Where bouts in Mo. do you live?? Im in S.W. corner and inspections here are in and out. Lights, signals, and horn. Bout all they ever check.

 

The city areas, St. Louis, St. Louis County, Jefferson City, etc. require the full test, the rural and small towns don't have to have the emissions part, I guess because they don't have the factories producing crap in the air like the cities so we have to suffer because of them.

 

Forget converting to a TPI. It is fairly expensive, quite a bit of work, and of little performance value. There are improvements that can be made to the Crossfire, or much better injection systems than the TPI if you want more than you can get from the Crossfire.

You've passed the test and that was your main concern, but you should be aware that your "tune" is still way off. My car passes with no cat(s). Your car cleaned up tremendously, with the addition of cats, but still didn't pass. Properly tuned, it could have passed without cats. I hope the dealer paid for the cats and all your trouble.

RACE ON!!!