hey i just took my 93 for emmisions i have all emmisions removed and no airpump and a straight threw exaust, my readings were
HC (PPm)
limit 231
my reading 575

CO
limit 1.23
my reading 4.57

now my question is i have a highflow cat will putting the cat on make that much of a difference? (and for those who say put it on b 4 i went the first time, my clutch is slipping i have to take the exaust off to pull the tranny so im goign to do it all in one shot) i knew i was going to fail but my temp plate expires soon so i wanted to get plates on it and worry after.

now my question is will the rx7store highflow cat bring my numbers down that much, what shopld i do. i was thinking of puting a cheap universal cat near the tailpipe so i could run 2 cats just to pass then take it off rite after. would that work??? or would it make my engine blow. another thing ive heard of is using an electric pump to send air to the cat were the airpump goes. dose anyone know were to get that pump or if it has worked??? thanks guys any ideas would help. im more concernd about if a cat will bring my numbers down that much because its a big difference thanks ~zach

 

You will need a cat (just buy a used stock one) and an airpump to pass. A cat alone will typically not do it.

 

Try cataclean or a gallon of methanol. My readings were high and i put a bottle of cataclean in done a ten mile run and it passed .cheep fix.worked for me.Rix

 

bump anyone else??

 

There's a huge volume of information on this in the archives.
In short: cat & air pump, drive hard on the highway before you go in.

I passed the MD sniffer with a 3" exhaust, high flow cat, and an un-tuned pfc.

 

The air pump would for sure drop the HC & CO, you might need an O2 sensor to lower your CO (too rich), having said that, both original Cats could bring it down enough to pass. The cats will clean a lot of emission, the air pump main purpose is for cold start to burn all the HC when the choke is on, but you still have the CO which is the burnt fuel in the combustion chamber, and thats why I said you might need an O2 sensor! If your car is setup to run rich (injectors, computers, etc) you might want to lean it out a tad. So many variables but that what I could think of for now. In California we do a visual check (not sure about CT) and if your air pump is dissconected it will fail. An extra Cat at the muffler ain't gonna do it unless its very close to the original Cat because it needs to get up to temperature before it starts to work (500 F). Also check your plugs.
Hope this helps, and remember there is more involved than what I just mentioned.

 

A catalytic converter works best when air fuel ratio is close to stoichiometry (A/F ~14.7). That how it's designed normally (being slightly lean of stoich is better for HC& CO, being rich is better for NOx, and vice versa). Since our dear rotaries run so rich they put the airpump to bring the exhaust A/F ratio much closer to 14.7 for better cat & emission efficiency.

CO get higher when the mixture is rich when HC are normally a sign of incomplete combustion (which is also the case when the mixture is too rich).

 

yea i have 2 o2 sensors one in the dp and one on the mid pipe i got a highflow cat and i have an air pump on its way, i just wanted to see any other tricks just to insure that i pass ive heard denatured alcohol or methanol etc but idk aobut that... i jsut wana pass lol

 

The above is true, but I think NOX is no factor since it was indicated that HC & CO are high, NOX only measured on ASM (dyno) if its a 2 speed idle test NOX is not an issue. The cat needs HC, CO & O2 to create CO2 and it will not do a whole lot if its not warmed up or up to temp. Therfore I mentioned the O2 sensor for excessive CO and HC anytime the O2 sensor is malfunctioning and being bias toward rich it will also have high HC. The air pump: as mentioned before, HC (gas) does not burn without O2, hence the air pump diverts to the cat when cold, after warm up it diverts to intake thats why I mentioned to lean it out a tad, after all your trying to pass smog not do a hot lap for qualifying.

Re the Hi flow cat, it will be OK if its still in a fairly new condition, assuming you do some correction to the HC & CO. I would change the oil if it contaminated and check the plugs and replace if needed. The goal is to pass smog!!!

 

jsut checked the o2s and there clean and i jsut got my airpump today so i will be putting that on and ithe plugs and oil both have less than 50 miles on them and the cat has zero. im goign to try it with the air pump and cat and i have about a half tank of gas so im going to throw in 2 gallons of methanol/denatured alcohol one or the other. i also have a carbon cleaner for cleaniong valves on piston engines i DONT KNOW what it will do to a rotary so i probly wont do that but im geting my clutch friday and going for emmisions tuesday so i will post how i do.

i also work with a guy whos friend dose emissions about an hour from me and can HELP me pass

 

alright back from the dead put on a highflow cat and airpump and 3 gallons of methanol and still failed off by .44 for hc and off by 2.7 hmmm im going to replace the o2 and if that dosnt work im going to sell the car, part it out, or sell it as a roller and put the engine in something 85 and under( i just so happen to know were theres a 67 mustang that needs a motor) lmao jk damn rotarys why are they so damn adicting there like crack....any one have any more ideas

 

A clean looking O2 doesn't mean its working!
Could you rephrase the above ^^^

 

If you wanted to pass emissions, why did you remove all the emission equipment?

 

unfortunatly i didnt it was removed when the non seq mod was done, i put the air pump back on and hard wired it to a toggle switch and ran that to the highflow cat that i have on. i want to pass or im going to look for a stock rx7

 

sorry im geting a NEW O2 and i was over the limit by .44 for hc and over the limit by 2.7 for co

so i hope changing the o2 will bring the co down

 

IRP is not too far away from you in Clifton, NJ if you need a professional to look at the car and/or correctly install emissions equipment. Shouldn't cost that much.

Might as well work with what you have if you know its good. No telling what other issues another car might have.

 

well i put my car up on the lift this morning and much to my dismay i found that when i came out of my driveway it bottomed out and ripped the zip ties i had holding it up so the hose was dragging for a good 20 miles( left a good 6 in tearin the hose) then i went for emissions....... so the numbers i got above are with the air pump connected but not to the cat lol... so lets see how she dose with 5 gallons of e-85 and the air pump hose hooked up this time.... wtf cant win

 

Theres nowhere in CT that will just let you pay to pass? What kind of state is that?? Wheres the corruption??

 

They just couldn't care less in my area. The Jiffy lube guys just look at my car, look puzzled, kick the tires, and just send me on my way.

I always love the spec sheet they give you that has the catalytic converter box checked in the visual inspection section. It's a 3" SS pipe all the way back. Not even a muffler that remotely looks like a cat!

 

I took mine to an Express Lube where they swore they knew HOW to get a 93 RX7 to pass. I watched them as they tried to do so and the screen came up red about a dozen times before they sent a lackey behind the car to do something with the sniffer, and bam, PASSED.

Good for another year. Hope you can find the same type shop who is willing to work with you.

 

ive looked and looked and no one will take money around here i have to go on the rollers adn they have cameras in every emissions station , my ex boss owns a car dealership so if i dont pass after reconecting my air pump agian (hopefully the hose dosent fall and break agian) im going to ask him for one. BUT if i lived in ri or mass i have good friends that own shops that said theyed give me an inspection and emissions sticker.

the only problem with that is im in ct and i go to college here so it wouldnt be worth changng adresses to do my car, and ive already thought about geting a po box there but they crack down hard if something ever happend and id be royaly fucked. so hopefully i pass wit hthe hose conected and a quarter tank of e85.

if not ill either 1) sell my car, 2) track the car, 3) 2jz swap, 4) do a full e85 conversion, 5) or get this guy to dance untill im exempt form emissions im leaning twords the last one.

 

I'll find you a place to do it. I got some Honda people in CT that I KNOW cant pass legit. I'll send you a PM when I find out. Where in CT are you exactly?

 

thanks bro thad be great

 

did you get a smog after changing the o2? If yes let me know the results.