I've got the full RB true-dual exhaust and REALLY don't want to take it off temporarily to pass emissions... I'm currently very low on gas as it is, so I'm thinking maybe put a gallon of denatured alcohol in there, and then use my SAFC/wide-band combo to lean everything out? Wonder if it's even possible... I search 5-6 pages, but I never saw a thread where someone was trying to pass with no cat.

Opinions...?

 

Thats because it is 100% impossible. A normal car would fail miserably without a cat, and a rotary is that much worse. It would probably fail from across the street.....

 

Unless it's an old Civic CVCC.

 

If you lived out here there'd be ways...

But no, it's impossible to pass without a CAT. Without something such as the air pump it's still impossible to pass. Don't quote me on it, someone might have somehow, but no way would you pass visual.

 

We don't have visual inspections.

 

Oh, well just another reason why CA is ghey

 

Slip the guy doing it 100$

 

i like this idea

 

Ive heard of a guy with a Dodge Omni GLH with a turbo 4 cylinder pass with no cat.
He had a dummy exhaust tip and the real exhaust dumping under the car.
I dont know how dumb your inspectors are, but he managed to pass since there was no visual.
Not exactly sure how youd do that with true duals while attracting too much attention (read decibels) to where ever the exhaust is really dumping

Worth a try?

 

^ now theres a great idea!!
just run down pipe with fake tips all the time!

 

I down know how much fooling you would do with an unmuffled rotary though.
Should would be a lot of loud noises coming from the everywhere but the tips!

 

Just a note: My friends Volvo passes emissions with no cat.

Another note: Rx7s are THAT bad at emissions. The FC TII I sold Passed CA emissions with 0 HC and 0% CO at idle and revved up.

 

note: every one is talking about Other Cars passing.The are NOT rotary engines.there is a big difference.If you stand behind your car and Smell anything at all,It won't Pass..mark my words..the Car needs MINIMUM a good cat,,and an air pump to the cat wouldn't hurt either..That is the Problem with modifying the car to get HP out of it,while the car is in an Emissions Tested STATE.,.you have to Still Comply to the Regulations when it comes time to Take the test..if not,you suffer the wrath of the sniffer.

 

You don't have a prayer of passing without a cat and at least a direct feed from and air pump to the cat. Rotary's idle too rich to pass without thoes as a minimum, and even so you might still need to drop some alchol in and play with the SAFC.

Lot's of normal cars can pass emmisions without cat's. In fact, pretty much any economy car that is running deciently well and tuned up at least half-assed will. Cat's only help the exhaust burn off any of the fuel that the engine didn't burn, so if it's a very fuel efficient car that is running properly then there is very little excess fuel to burn in the exhaust pipe.

 

Erik-

You are not going to pass. Buy a cheap converter, weld it up with a couple of flanges and replace the muffler or resonator for the day of the test. Store it in your garage for the next test. I did that for a couple of years. Pain in the ***.

This rest of this thread is speculative bullshit. NOBODY passes without a cat, unless they are bribing a tech.

The sniffers detect exhaust dilution, so you can't use a fake exhaust tip or just pump so much air into the exhaust that the pollutants are reduced in concentration...

Piston engines don't pass without cats. It is not just about hydrocarbons, boys. It is about NOx and CO as well.

I challenge anyone to produce an actual passing test from a car that is verified to NOT have a cat.

This will turn out to be 'I know a guy who knows a guy who has a friend who...."

 

True
Bullshit. Prove it.

 

My car's reading 1200 HC and 5.1 CO.

WITH a cat and an air pump.

I say it's hopeless

 

Yeah, I agree with most everyone else here. I tried it, didnt work. NA's run a little rich, especially compared to the TII's. I tried to pass without a cat, and a new engine. It was always close, but never passed. If you ask me, rotaries ARE worse about emissions. I managed to get my old 87 JEEP Comanche Pickup to pass with a full exhaust minus the cat. Same thing with an 86 Plymouth Reliant.

2 SOLUTIONS.

1. Temporary cat, Air Pump set-up. You CAN quote me on this... IF YOU DONT HAVE AN AIRPUMP YOU WILL NOT PASS !!!!

2. Register the vehicle in a neighboring county, if you know someone who will let you borrow their address. (Here in TN, they test per county, not state wide. Hamilton County, (Chattanooga, and surrounding suburbs), was chosen, however none of the surrounding counties are testing.

Also, This IS spreading. Its only a matter of time until Emissions Testing is mandatory everywhere. Unfortunately, this means many limitations as far as upgrades are concerned. Keep that in mind if you live in an emission free area, and are about to pull the airpump/emission system.

In TN, at 25 years, 2013 for me, the car can be registered as an antique, and thus exempt from emissions, However, there is a lot of red tape especially here in TN.
1. Un-modified engine
2. Only to be driven on Saturday and Sunday. (to club related activities) If caught driving on M-F the antique registration is revoked.
Many other States and area's are less strict.
One good thing is that its a one time fee, and is good as long as you have the title. So after you had it, you could pretty much do whatever you wanted to it.

Good Luck.

 

Its not hopeless. My old numbers were similar to that. It took me 2 years, maybe 8 registration tickets, and 500-600 dollars, but I finally got it.

One tip. A high dollar cat makes a big difference. Also lean it out a little, I assume by the numbers that its an NA.

Everybody's going to be just fine. Good Luck

 

hey erik, you might be able to pass wouthout a cat, the seattle station passes catless RB engines all the time i would know since i use to work at the emissions station. PM me and ill guide you through the steps on passing a modded rx7 in seattle.

 

Here in the UK cars made before 1991 have nice easy test to pass. Therefore i dont need a CAT to stay legal, trouble is once I had my motor ported it still took 3 attempts to pass.
In the end I just took it for a thrash to get the exhaust really hot and the test guy did the test stright away. It passed just.

Stock motor passed easy with no CAT.

 

Good thread guys, I appreciate all of the input.

Haha, not likely... I was talking to the co-owner of the particular N/A RX-7 in question, and were discussing possible options. I had mentioned the idea of running 50% alcohol and then tuning the SAFC to dangerously lean. He came back and told me that both him and his roommate's VW Corrado's passed emissions with NO CAT--they are both straight-piped with a resonator. His is a 93 SLC VR6 with heavy mods. His roommate's is a 92 SLC VR6 with a bored 2.9 engine... So yes, I *could* get those emissions paper's if I wanted to, but I don't care enough about proving this point to another person, because it's already been proven to me.

Thanks for the responses guys. And yes, I do have a complete stock exhaust with cats and air-pump that I could install, it's just I don't want to go to the trouble... I finally have the car set up perfectly and don't want to start climbing under it if I don't have to. LOL.

That being said, I have found another loop-hole to pursue, so I will post back if I'm successful.

 

Sweet, got my tabs and registration renewed. Sadly, I guess I won't have to investigate the "no cat, 50% alcohol, super-lean theory"... Thanks for the responses.

 

Because he TOLD YOU?
Uhhh, no offense intended but I rest my case.

Gullible:

http://en.wiktionary.org/wiki/gullible

English

Etymology

gull + -ible

Adjective

gullible

Positive=gullible

Comparative=more gullible

Superlative=most gullible

1. Easily deceived or duped; naive, easily cheated or fooled.



Seriously, good luck with your loophole.

 

Your going through a lot of trouble to argue a point that you are wrong on. How much good do you think the cat on a 15+ year old car is? Probably not very.

In a way you are right though, since a lot of places actually have to look and make sure there is a cat on the car then yes a small piston engine without a cat will fail emissions... because it will fail the visual check, not the actual emmissions test.

When I lived in Vancouver where there was emmission testing, I simply registered my car in a different region that dosn't have emmission testing. Now where I live, I don't have emmission testing and only cars newer than '91 have a visual inspection for emmissions equipment. So my '88 needs dick all for emmissions ****.

I know of mutiple civic's and MX3's that have passed with either no cat or a hollowed out one, which will do just as much good as no cat. And I'm sorry but I have no interest in collecting the emmissions papers of friends and taking their exhaust systems apart to see if in fact there is no cat or a hollow car on the car.


Back to positive comments. To the dude who started this thred, glad to hear you got 'er registered without any issues.