How I passed smog with flying colors

[fisheric]

Hi everyone I just wanted to share with you my experience smoging my 1981 280zx turbo.

 

I had done a complete tune up and then failed my smog.

 

Next I turned my attention to all of my vacuum lines and also clean the engine with seafoam and then ran the car nearly empty and put two bottles of injector clean in and let them run through till the car died. I failed again, but this time I passed/failed the opposites test that I did last time (The tests I failed and passed last time were reversed this time)

 

I didn't know what to do at this point and I had pretty much run out of options and I read that changing a catalytic converter would not help pass smog.

 

Not pass my ass! It cost me $90 and 20 minutes to have a guy swap out catalytic converters.

 

My car ran sooooo good afterwards, it even has a nice rumble now

 

When I passed the numbers on the test (i cant remember exactly which ones) that were 20 - 50 points above passing were down to a reading of 3, 6, one was like 33.

 

The car is virtually zero emissions.

 

I just wanted to let everyone here know how I passed. In case you are having trouble passing smog I highly recommend trying this low cost fix.

 

 

Oh yeah, and the last test I had to do extra testing because my car had failed so badly before it was considered a gross polluter.

[woldson]

Sounds like your old one may have become pluged up.

Great to hear you got her past:)

[dr_hunt]

Just FYI, catalytic converters have a design lifespan of 5 years.

[240z!!!]

my car has no catalytic converters and ive deleted every piece of emissions equiment that was on it and i passed marta with flying colors.....if you put 2 bottle of rubbing alcohol in with about a 1/4 of a tank you'll pass everytime...the emissions tests for gas or co....and i actually found that my car idled a bit higher and was much smoother....oh and fyi thats an old mechanic trick if you take your car to some shady places to get the emissions fix sometimes they just throw some alcohol in it and you'll pass and wont know the difference

[MJLamberson]

To bad CA has a visual inspection.

[fisheric]

To bad CA has a visual inspection.

 

 

yes, too bad they have a test at all!

 

now they even outlawed the sale of new two stroke lawn equipment.

 

so we, the american public, who pays these politicians salaries have them do nothing but bother us and take our money while factories, The Main Cause Of Air Polution, in the united states get to spew forth their toxic venom into our air and rivers and drinking water.

 

I always wondered what kind of a person would sell out the planet they live on.

 

 

 

on a positive note I had a non-original gas cap and the smog tech told me he could have failed me because its not part of the oem emissions set up.

 

I told him he shoulda mentioned that before he took my money 3 times

[fisheric]

Sounds like your old one may have become pluged up.

Great to hear you got her past:)

 

yes you are correct. Im sure it was clogged. They car had been running rich for some time and i think that is what did it.

 

Just FYI, catalytic converters have a design lifespan of 5 years.

 

hehe, i bet they do. There was a poster at the shop I went to that said "catalytic converters do not get used up. if your cat is bad, something else caused it"

 

it was a poster from a cat company i think.

[kiwi303]

hehe, i bet they do. There was a poster at the shop I went to that said "catalytic converters do not get used up. if your cat is bad, something else caused it"

 

it was a poster from a cat company i think.

 

Yup, I agree with the poster, look up the definition of Catalyst in a chemical dictionary, it will tell you that a catalyst is a substance that triggers a reaction but is not itself consumed in the reaction.

 

IIRC cats use a platinum glaze over a base substrate such as perforated stainless plate or porous ceramic bricks which maximise the surface area of the catalyst presented.

 

That is why ZDDP was removed from SL oils to give the more modern SM series oils, the zinc compound was reacting with the catalyst in a separate reaction than the hydrocarbon/NOX reaction that was wanted.

[ww]

Next time, get a "pre-test". I think you're stuck with "gross-polluter" status for at least 6 years or 3 more tests.

 

I've passed every "official" smog test rather easily with basic tune-up's. Once you have all your vacuum lines working properly, electrical connections cleaned and making good contact, pretty much everything else is a cake walk.

 

For future reference, the cats on these cars are bolted on.

 

Congratulations getting it back on the street!

 

on a positive note I had a non-original gas cap and the smog tech told me he could have failed me because its not part of the oem emissions set up.

 

I told him he shoulda mentioned that before he took my money 3 times

[woldson]

Any car I've ever owned passed emissions with out a cat, with flying colors as long as it ran write.

I even have a saab that may have a cat with no internals that passes great too. Plasma torch and tig welder and air chizel..........

I miss the old ceramic days;)

[Tony D]

yes, too bad they have a test at all!

 

now they even outlawed the sale of new two stroke lawn equipment.

 

so we, the american public, who pays these politicians salaries have them do nothing but bother us and take our money while factories, The Main Cause Of Air Polution, in the united states get to spew forth their toxic venom into our air and rivers and drinking water.

 

I always wondered what kind of a person would sell out the planet they live on.

 

 

 

on a positive note I had a non-original gas cap and the smog tech told me he could have failed me because its not part of the oem emissions set up.

 

I told him he shoulda mentioned that before he took my money 3 times

 

Ohh, you may want to edit part of that...

 

As for cats not helping pass smog, they won't if your car isn't running right. There are tests in the FSM to test the thing, and to test the O2 sensor feedback loop.

 

With the feedback loop properly functioning, no vacuum leaks, and an engine in good tune, you don't need the catalytic converter to pass to 1981 specifications. My 73 passed to 83 standards with AIR injection, headers, and SU's.

 

The catalyst is there to handle 'excursions' where the engine goes out of the cleanest runnign range. There is some scrubbing done at all times, but when the car is cruising on the road at speeds above about 1500 rpms, and below 3300rpms it's on that O2 feedback loop and polluting the least.

 

As for replacement cats...a $90 cat will last you maybe a year. Chances are good it will fail again in two years for one of two reasons:

1) the aftermarket cat has taken a dump

2) whatever poisioned your original equipment cat (other than 250K+ miles) likely will burn this one up too. Usually a rich mixture from someone playing with the AFM.

 

New catalysts from OEM's have a lifespan of 10 years and 100K miles by statute.

 

Replacement catalysts have no such standards. If you are paying $90 for it, you are paying LESS than what a scrap yard will pay you for your old OEM Catalyst.

 

That should tell you something about how much more catalyzing metal there is in OEM units compared to aftermarket offerings.

 

Let me guess, the guy that did the work 'tossed your old cat away so you wouldn't have to deal with it' right? What a great guy!

 

He just made $100 to $150 on your catalyst, on top of what you paid him for his aftermarket installation.

[fisheric]

I believe that the car ran rich for a couple years before I bought it. When I got done tuning it up everything was running perfectly and I still failed my smog.

 

It was literally one day I went in and failed. Then I left and got the cat changed came back the very next morning and passed with "flying colors" whatever that means?

 

I couldn't find a shop who would do the job for less than $150+tax. He did it for $90 out the door and was able to see me the same day. Which was important because my tags were expired.

 

Honestly I knew that shops kept cats so they could recycle them. I just didn't know that you could get so much for them. That is a surprise to me.

 

Oh and mine may have been changed before because it was welded in place not bolted on like someone mentioned.

 

 

I only started this thread in case someone was in a similar position as mean and having trouble with their California smog.

 

I appreciate everyones input. I had no idea there were so many ideas concerning this.

 

Thanks everyone.

[fisheric]

Oh and everyone realizes that I am in California which I believe has stricter smog rules than other states.

 

So in some states maybe a car can pass more easily?

[woldson]

We know. Converstions on this matter only get shedded after while.

Advice: let it go..

[vspec]

I'm glad florida has no emission laws.

[HadesOmega]

HI sorry to resurrect an old post, well I gues its not that old. I was wondering what was making your car fail? The last time I got a smog check I passed with really good results now I'm getting really high CO. I'm thinking it is the catalytic converter its one of those 2.5" high flow cats. They said it might be the injectors but they seem to be working fine. Bleh I wish I had a 75 280Z hehe... Mine is a 76 with a L28ET

[Tony D]

The last time I got a smog check I passed with really good results now I'm getting really high CO. I'm thinking it is the catalytic converter its one of those 2.5" high flow cats.

 

1) Aftermarket Catalysts do not have any requirement to meet regarding longevity. There is a reason OEM catalysts cost around $1200 to replace: they have met testing and have been certified by the manufacturer to last the requisite time required by USEPA Dictates...that is 10 years/100,000 miles for some time now. A cheaper 'universal' or 'high flow' catalyst that is cheaper than an OEM unit is cheaper for one reason: They have less catalytic material, and no testing requirements to pass. If it is put on an engine and passes for a short period of time, it's suitable for sale.

2) As mentioned above in the earlier posts, slapping a cat on it will likely do nothing to the car---if it has something wrong with it, it will kill a new cat in short order. Likely your car is 'running rich' and killed/poisoned your new catalyst. This is done all over and because the cats are cheap, people don't complain that much.

 

Likely it is NOT the injectors (likely it's an input device that is giving false signals to the ECU and commanding it to run with full fuel), but those are the easiest to replace and charge money for...the next will be an ECU, then into the componentry like AFM and TEMP sensors, maybe eventually an O2 sensor... The FSM spells out very specific troubleshooting techniques, that even without a CO meter you can do at home to determine if your O2 sensor is providing a signal for the feedback loop. An O2 sensor is supposed to be replaced as part of regular maintenance, they DO go bad and when they do, they cause all sorts of problems like killing cats and dogs, and all sorts of other things---including Smog Techs...

 

Check your FSM in the emissions control section, and the EFI section. The tests are well delineated, and very simple to accomplish. Instead of letting a shop take you for a ride, confirm some tihngs on your own beforehand (the cost of the multimeter is less than the hour diagnostic charge at the shop!)

 

Sometimes a simple O2 Sensor change is all that you need to get working.

 

On the pre-O2 sensor cars (Like yours) that same line of thinking works as the multimeter will show you the resistance in the temp sensor line that causes 'cold start' fueling to happen, and run rich.

 

Sure, the car runs great---rich and fat, and full of rich best torque production...but it will kill that tired old catalyst you have (or that new cheapo the shop put on to pass last time).

 

Thing to take away from this is that hte catalyst is a scrubber device---these early cars do not CLEAN the exhaust leaving the car, they simply are there to scrub HC and CO excursions from transients (acceleration, stabs of the throttle, running WOT uphill in overdrive, etc...) When the car is running in closed loop (all the time in these cars) the emissions are VERY LOW and the ECU is calibrated to do that. (on newer cars with a MAF or O2 sensor that has a trim capability, the emissions can go even lower...but they purposely run at a given cruise Air/Fuel ratio to leave enough unburned fuel in there to keep the catalyst hot enough to actually convert many other compounds out into their base elements...they run 'richer than needed' to promote cleaner exhaust out the tailpipe through better catalytic action---a totally different reason than why catalysts were put on the original 75-84 cars)

 

As long as your input signals are correct, the output to the injectors will be correct. It's a very simple system. If you can, download the "EFI Bible" from any of the several online sources and read it---it makes the technology crystal clear, and shows how all the parts interact. The system is very basic, and it's not different now than when it was a carburettor. Give a carburettor the wrong fuel pressure, and it will not work as designed. Change the air density and you run rich or lean.

 

Same with this early EFI, you just have Temperature, RPM, and Air Flow to worry about in the most basic forms. As long as those inputs are good, your output will be good. And the FSM and EFI Bible show you in plain clear verbiage how to isolate and check each of the inputs and outputs to determine what is wrong.

 

It should only take 45 minutes to check all inputs and outputs with a multimeter following the FSM instructions relating to the EFI System. After that, 'trust your instruments' and do what they tell you to do. In almost every case people diagnose what is wrong, out of the gate following the FSM instructions, and then convince themselves 'it can't/couldn't be that easy!' and revert to shotgunning or guessing at popular mythical solutions...usually causing more problems in the process!

 

I can't tell you how many times I've gone to someone's car, reinstalled all the original 'replacement' components, and started from scratch finding a simple problem that required minimal time and $$$ to fix. Only to have them say 'I found that, too, but I convinced myself it couldn't be that simple, and replaced the AFM instead!'

[Gearshredder]

I heard somewhere that a catalytic converter can also make it look like your car is closer to perfect emissions because of sort of a burn in period. Also why you would pass with flying colors with a new Cat, high flow or not.

[fisheric]

I heard somewhere that a catalytic converter can also make it look like your car is closer to perfect emissions because of sort of a burn in period. Also why you would pass with flying colors with a new Cat, high flow or not.

 

 

that is interesting. Because I put on my after market cat and no less than 10 miles later had the smog check and the numbers were so low that it seemed impossible. i forget which categories, but somthing like 0, 2, 7, 22.

 

in my case when I first got the car it was running rich and the damage was already done.

 

its been a couple thousand miles now I wonder what the results would be like today.

 

does any know an approximate life-span of those cheap after market cats?