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Will E85 with no cat pass smog?

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1stGenTSi

15+ Year Contributor
323
1
Apr 8, 2005
Austin, Texas
As the title states I need to pass emissions testing and don't want to put a stock exhaust back on. Since E85 produces significantly less tailpipe emissions than gas could a cat-less car pass when burning E85 or E98? Anyone tried it?
 
NOt sure, but soon i'm hoping to go down to a local guy i know with a 5 gas analizer i'm hoping to try and get an emmisions passing tune from mine and that's the combo i run.

I imagine that a cat, 190 t-stat and working EGR are still going to be needed. I've passed smog on a stand alone before and those were the 3 things that no matter what i couldn't tune enough to pass the test (well, the EGR was for visual inpection along with the cat, but the cat actually made a difference) the cat and t-stat helped the gas levels come correct
 
doesn't Texas have a visual imspection also,if so having no cat will flunk your car. GOOD LUCK
 
If it's like AZ then if your car is low enough they will just assume you have a cat since they cannot see it and don't want to get dirty for their $8/hr trying to find it. My car didn't come with a cat, it has always passed the sniffer on plain ol' 91, E85 burns even cleaner.
 
when they had testing in minnesota the first thing they did was look under the hood then they would walk around the car with a mirror on the end of of pole to see under the car. It was great when the got rid of it here completely.
 
I hate to bring back an old thread. But I am just as lazy as OP and the $8/hr emission workers. So what's the conclusion, guys? Can I pass emission running without a catalytic converter and on E85?:beatentodeath:
 
It depends on each state, but whenever an emission is required, it requires a cat because that's the vital part that eliminates/lowers most of the harmful chemicals that the engine emits. I just went through a few smog check stations where I live and they are pretty strict. The visual inspection includes checking for the EGR valve, working charcoal canister, catalytic converter, hoses, anything emissions related. If for any reasons they don't care to do a visual inspection on a cat and your engine emits lower emission values, then of course you going to pass. Someone above even mentioned that he's passed emissions with 91 gasoline, but I think that's impossible without a cat. Everyone knows that cars burn E85 cleaner and emits lower emissions, but we don't know exactly by how much. But if E85 without a cat emits lower than the maximum levels of emissions, then of course you'll going to pass if no visual inspection is required or the smog tech simply ingonre that procedure or you pay the tech a little bit more to ignore the cat visual inspection. Check the testing requirements of a smog check in your state.
 
E85 still makes hydrocarbons & having a cat helps reduce them a whole lot. If you have a really, really good tune & a really good running motor you should be able to pass emission without a cat. Most emission devices are for when vehicles are older & wearing out, not when they are new (& startup these days). My experience shows that if you can't pass with gas you won't pass with E85 either.
 
if you have link and a wideband, enable WB02 simulation and change the switchover voltage from 2.5 to 3.0. This will cause you to idle at 18:1 afr, less fuel, cleaner exhaust.

Passed emissions sniffer with no egr and no cat on 92 pump.

stay out of boost, pass emissions, then change the crossover voltage back to 2.5. I usually make this change 1 block away from the facility, then change it back after I pull out of the other side.
 
Silent_White, that's a very good tip. Will have to try that on mine.
 
From my experience, every single time I brought one of my cars in for emissions everyone seemed extra diligent......they dont want you to pass. They take one look at your car and grin......My 1992 talon, last year for emissions mind you has a electric cutout before the cat. They have a mirror on a pole and went through my entire exhaust and got on the phone......Im sure they were checking the laws but i did end up passing.Like they say ......your success vs failure is dependent on whether your prepared or unprepared. Never make assumptions....go in assuming the worst and walk out with your paper :f-u:
 
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