1997 Chevy Cavalier still wont pass emissions... What now?

At 152k, I'm putting my money on the Cats. Fresh oil change, Guranteed to Pass, clean throttle body and PCV, 93 in the tank with a bottle of isopropyl alcohol. Get it on the highway and blow it out. Straight to the shop for an inspection after the blow out. Nice and HOT....Sell the car ASAP.
 
They are. But they only adopted it a few years ago - so shouldn't it mean there using a 1997 federal standard for the car in question - not the California standard. They can't back date such laws.

I think that's what they do......Use the '97 federal limits on a '97 federal emissions vehicle.
 
Per your other thread it's idling poorly. I still say do the intake manifold gasket. This explains how it's both rich and lean at the same time.

Also a fresh oil change will soak up HCs temporarily. If you can pull the EGR valve off you can clean its passages out with a frayed bike brake cable in a drill. Run the car with the valve off, it'll make noise from the exhaust side and idle fast/ poorly from the vacuum leak. If it doesn't do either your passages are still plugged.
This, if the intake is leaking that could lean things and cause Nox to go up, lean misfire might raise HC.
When you go in to test again, try to figure how much gas you have in the tank , and add some E-85 but not too much, just enough to get the total mix to E-20 or so. Alcohol burns cleaner, cooler.
 
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What state are you in that they actually use a sniffer on a 1997 OBD2 car?

I agree that looking at long term Fuel Trim is next before firing the parts canon.
Colorado is in bed with the epa. They're now talking about raising the emissions testing from $25 to $50. Coloradans are over it. What should I be looking for on the fuel trim. I've read a few other forums saying that this could be an egr problem which is a $300 replacement or iac which is $120ish.
 
At 152k, I'm putting my money on the Cats. Fresh oil change, Guranteed to Pass, clean throttle body and PCV, 93 in the tank with a bottle of isopropyl alcohol. Get it on the highway and blow it out. Straight to the shop for an inspection after the blow out. Nice and HOT....Sell the car ASAP.
I did the high octane, bottle of Cataclean, oil change straight to the emissions center. The weird thing is that initially I had was one leaking fuel injector. I ran a bottle of Cataclean through the system and only then did I start to have misfires. I hope it doesn't require a catalytic converter as that will cost me out the nose to get and have installed. If it passes emissions I get two years without another emissions test. I'm seriously considering trying to figure out how to get a "get rid of emissions testing " on the next round of voting. Now since my initial license plates weren't renewed within 18 months Colorado kicks them out of the system, so I have to get new plates.
 
Did you look at the waiver? You would almost be there with the IAC and EGR. I’d try the alcohol in the tank first. Do some reading online to see other people’s results.

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What should I be looking for on fuel trims? Not well versed in that.
Fuel trims will be a percentage. +/-5% is perfect. +/- 10% is tolerable. Ideally you would measure under load at a constant speed, but in your case I would say you want to measure them at whatever speed the test station is using?

+ means its adding fuel (running lean)

- means its taking fuel away (running rich)
 
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That will probably ruin every gasket and fuel line in a car this old.
Nah, worst I’ve seen is plugging your fuel filter.

I’ve ran it in a 1980’s truck a few times and nothing happened,

Heavier Ethanol blends slowly over months/years dry everything out, but not significantly faster than e10. So one tank of e20/30 won’t do much.

Running more than 10% like the recommended 20% will probably get you to pass emissions of at least one type. Improving both is questionable but not impossible.

Heavier E-blends are easier to pass emissions because ethanol is an oxidant that reduces Hc (in general).

Key is you want the car driven long enough to be all around hot when it goes in for emissions .

As others have said if you have already $$$$ to fix things emissions related persue the hardship clause and if you can prove you replaced enough $$$ on emissions things they might give you a 2 year pass.

I would not be afraid of guaranteed to pass in your case, just make sure a fresh oil change is in there.

MMO can cure rough idle which in of itself can cause an emissions fail under certain circumstances.
 
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Nah, worst I’ve seen is plugging your fuel filter.

I’ve ran it in a 1980’s truck a few times and nothing happened,

Heavier Ethanol blends slowly over months/years dry everything out, but not significantly faster than e10. So one tank of e20/30 won’t do much.

Running more than 10% like the recommended 20% will probably get you to pass emissions of at least one type. Improving both is questionable but not impossible.

Heavier E-blends are easier to pass emissions because ethanol is an oxidant that reduces Hc (in general)
Might fix his hydrocarbons but would make is NOx worse no? Maybe no - I suppose if its not because its lean but due to something else - EGR - then maybe?
 
Might fix his hydrocarbons but would make is NOx worse no? Maybe no - I suppose if its not because its lean but due to something else - EGR - then maybe?
Guys who owned their own sniffer did tests back during the first $4+ gas.

Even in 1993 era cars they never actually went “lean” on e blends up to 40%.
HC would go down, NOX was ??? and sort of random but VOC could go up.

Bad pcv and bad egr can sometimes be covered by eblends. Higher eblends can sometimes cure rough idle in the case that the banks are uneven as well because you are dumping in a larger volume of fuel at idle as the trim moves , it’s strange but ethanol blends run smoother while lean.
But can just as easily make idle worse depending on why the car is doing it.

If his gaskets are leaky MMO will cover that problem right up like a bandaid. Put many miles on a damaged 3800 that would stall at idle constantly, using mmo it would then idle consistently and run better in general.

Band aids work great to get you along just long enough for a test.
 
If he is in California or a state that follows Ca smog rules(I think there is 11) you gotta pass or scrap the car. Selling it out of state is also an option.

Ca requires cars back to the1976 model year to have tail pipe emissions tested. Then they went further and make you run it on a dyno in hopes of it failing
He could sell it anywhere else in CO. 99% of the state has no testing -- although there is always quiet whispering about changing that.
 
I have used a gallon on E85 to 3 gallons or regular gas (approximately, close to an empty tank) and added a bottle of Heat. I then ran it up the interstate to get it nice and hot before the e- test. This was my go to for bringing the hydrocarbons down for the CO emission test. I always fuel up right after to dilute the remaining E85 in the tank. Never had an issue.
 
At 152k, I'm putting my money on the Cats. Fresh oil change, Guranteed to Pass, clean throttle body and PCV, 93 in the tank with a bottle of isopropyl alcohol. Get it on the highway and blow it out. Straight to the shop for an inspection after the blow out. Nice and HOT....Sell the car ASAP.

Don't use drugstore alcohol, it has water in it.

Maybe a few bottles of the alcohol sold to stop fuel line freezing in winter, called Heat.
 
Don't use drugstore alcohol, it has water in it.

Maybe a few bottles of the alcohol sold to stop fuel line freezing in winter, called Heat.
HEET. :) Pedantic, yes, but the correct brand name spelling eliminates any doubt. There are also red bottles of HEET with injector cleaner -- not that I'm suggesting OP's problem would be remotely resolved with injector cleaner. I've actually just always wondered if the cleaner HEET uses is worth a darn (I got a 6-pack years ago on Walmart clearance)
 
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