im happy i failed my smog test, now I have a reason to spend more money on my vette.

Heres a list of things i did before the test (only the stuff that effects emmisions):

seafoam in gas tank
new rotar
new dis. cap
new plug wires
4 new plugs (ran out of day light to put the other 4 in)
new o2 sensor

OK, so heres the results from the test:

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

CO2 Allowed: 15.000
CO2 Result: 59.2111

Every thing else passed and there were no codes reported from the ODB I interface.

So I knew I was gonna fail, I can get a wavier for $450, and its not a big deal to spend the money. I was planning on it when I bought the car. Since I am having to get stuff to pass the test I have a list of stuff that I have to spend the money on repairing:

1. o2 sensor validation (just put a new o2 in before the test)
2. Fuel Injection / Delivery (hmm, its a cross fire, they always burn rich I ran some seafoam through last week.
3. Mixture Control
4. Primary / Secondary Ignition
5. Vaccuum / Pressure system
6. Engine Mechanical
7. CAT and/or Air system

whats the easiest way to spend $450, i think exhaust. So im looking for some new cats that will fit a stock 1984 c4, If im gonna spend the money I want to spend it on some hiflow cats. Not that its a performance car, but i eventully want it to be one. So if im gonna spend money I want to get some performance exhaust.

I feel heat inside the car which tells me that the cats are plugged, and the exhaust is loud for being stock which tells me that the baffles in the muffler are gone.

but i want to make sure that I get good quality parts the first time around. I know you can spend thousands on good exhaust. My problem is that I can prolly come up to close to a grand to spend. So I need to know which would drop the numbers the most. Cats, or mufflers. if i go for the mufflers i want the flowmaster 40's. If i go cats I want to get the ones from random technology. Will these hook up to the stock "headers" (for a lack of a better term, im a drive way mechanic).

Also would getting a new Hi volt coil help the emmissions get cleaner?

basically im wanting to double check that doing this stuff will improve the emissions before I spend the money that goes to getting the waiver. (emmissions must improve after the work has been done to qualify for the wavier.)

 

Where do you live again? I think I developed a cough recently ...

 

What year car? Mine had just one cat, in the middle. If you buy a direct fit replacement cat then you could swap out your old for the new. You may want to goto true dual exhaust with two cats. It's nice! A new coil wouldn't help. The exhaust being loud and the cats being plugged are contradictory! Shouldn't it be quieter with plugged up cats?

 

I will take a photo tonight if i can squeeze my camera under the car.

it appears to be true dual exhaust. It is a 1984 C4. It has 2 cats, and 2 mufflers.

 

You've GOT to be kidding!
Your HCs are 700% (seven times), and your CO2 is 400% (4 four times) the legal high limit and you want to "fudge" on the test??? That car must run like crap. I have a 1978 GMC 3/4 ton 4X4, with a Quadrajet, 400 cid engine, with HD emissions (no smog equipment) that passes your test. HD emissions on that engine, in that year, means NO EGR valve, NO smog pump, and NO catalytic converter. Besides the lack of smog equipment, the heads have been milled and it has a "stage II RV" cam in it. 200,000+ miles and the cylinders have not been bored. Probably for less money than you are prepared to spend, you could actually FIX it. Otherwise you're going to spend $450.00 cutting off your nose to spite your face. And the car will still run like junk.

RACE ON!!!

 

just because you spend $450 on exhaust that may not satifiy the ref. do you have a code reader, see if you have any code stored first. i had a web page that helped tell you what to check for each reason it failed. cleanaire.com or some thing? i failed for high hydrocarbons.
oh check out flowmaster on jeg's web page, $107 each..

 

Mufflers will have a ZERO effect on the smog output of your engine. If the smog czars in your state allow the expenditure for mufflers, let us know what state that is so I can wear a gas mask if I have to come through there. Where's Bogus when you NEED him???

RACE ON!!!

 

I'd recommend replacing your cats and going through the EGR system, seems these two are the usual suspects in these cars failing smog.

 

Well how long before you took the test did you put the Seafoam in? It could have started burning out 22 years of crud in the engine while you were taking the test wich would have made you emissions worse

 

Very good input from all of you. To awnser some questions

a. I do want to FIX the problem, just not sure how the $1000, that i have would be best spent to resolve the problem.

b. A wavier is acceptable to me cause the car is going to sit most of the winter, but I have to have plates on it for it to be parked on my property. In the spring I hope to have saved enough money to get a new engine for the car.

c. It was not my poor maintaince that got the car to this condition. I just bought the car. I plan on restoring the car eventully. Just need plates so I can keep it at my house since i lack a garage.

d. I put the seafoam in, ran that tank of gas out, then ran about 1/2 of the next tank out.

 

There is a new O2 and no codes, could the timing be off to cause such high emission readings?

 

I'll presume your not in CA, because most places in the State allow you to store your car on your property (some zoning laws do make you keep it out of sight) regardless of smog or current registration. Your car is running rich and though it may need a new CAT, you could easily burn a new one up if you don't repair the underlying problem. I'd invest a $100 or so in a scanner. That way you can determine why the ECM thinks it needs so much fuel and make the necessary repairs.

 

A.) You can probably fix the problems for less than $1000.00. As suggested, have, or do a scan. HCs are unburned fuel molecules. That indicates a miss for one reason or another. A miss can come from faulty ignition, overly rich or overly lean fuel mixture, EGR valve problems, etc. A saturated Evap canister or gasoline in the oil can contribute to high HCs, also. The CO2s come from a mixture that burned, but was too rich. The scan should tell you a lot, but I'm guessing that somewhere along that fancy intake manifold, you've got a vacuum leak. While you're at it, be a sport and go ahead and install the other 4 spark plugs.

B.) I understand the logic of the waiver, but I'm guessing you can accomplish the same thing for a whole lot less money. You could rent a garage to keep your unregistered car out of plain view, while giving you a place to work on it. It seems to me that $450.00 for a waiver, pretty much goes down the drain.

A catalytic converter was mentioned. It can help hide minor problems. But also as mentioned, if the engine isn't really right, the expense of the cat COULD just go down the drain, too. Neither my 1978 GMC 4X4 nor my 1984 Corvette have cats, so as helpful as they CAN be, they aren't necessary to sniff clean.

RACE ON!!!

 

I got the little key scanner thing today. Hit the upper right two pins of the obd interface. check engine light didnt blink or any thing. looking at the paper they gave me it says "NO DIAGNOSTIC CODES REPORTED".

they also did a visual inspection, all componets passed. Basically means there all there.

My friend is going to check the timing for me this weekend. But looking at the report, theres nothing thats consistant. Some spikes are while the car is accelerating, some are while its slowing down.

Others are all over the board when the speed is close to staying the same.

Most of the stuff im reading is saying its a mixture air/gas ratio problem.

am i correct thinking that if the timing is ok, that it would be a vaccuum issue?

or could it be something like the coil isnt supplying enough spark to get a clean burn?

 

Timing can affect smog output, but not the "mixture air/gas ratio". IF the timing is OK, it is NOT necessarily a vacuum issue. Although, that IS a possibility. It doesn't cost anything to check for vacuum leaks, so that would be a good thing to do. They seem to be as big, if not a bigger problem, with the Crossfire than most sbcs.

The next thing to do is to trouble shoot your ECM. If it can't spit out any codes, not even the, "all clear", twelves, there is doubt it can control your engine. My guess is that you don't have a factory service manual. If I'm correct, go HERE and order one. Then spend some time getting familiar with it. Subtract the $100.00 for the manual from the $450.00 you were planning to waste on the waiver.

RACE ON!!!

 

Hey EFI-CFI ...correct me where I'm wrong here but doesn't the 84 crossfire set up put the EGR in a "lousy" location on the intake? Thus causing an excess build up of carbon at that location on the underside of the intake? If so couldn't that cause problem affecting emissions?

 

manual is in the mail.

 

You have taken a giant step forward toward a wealth of help and information.


Like there is a GOOD location for an EGR valve??? The EGR valve is located in the far right hand (the car's right) rear corner of the intake manifold. Inside of the base of the manifold there is an "EGR channel" cast into it that makes the EGR dump right into the center of the manifold. Some people think there is a performance gain to be had by removing the EGR channel. If that were done and the EGR were allowed to continue to function, the EGR gases would be very unevenly distributed and would choke off cylinders #6 and #8, badly. In it's "as designed" form, the Crossfire, EGR, doesn't present any unusual problems.

RACE ON!!!

 

My 87 just passed the Ca. test today (dyno). I have no precats just an aftermarket center cat and no mufflers just tips. I just completed my 4+3 manual to auto conversion and the tech didn't say squat!

 

Drewber, are you in So. California?