Here are the results with a bonez straight pipe and everything else stock:
HC:
limit 168 ppm
my car 1003.2 ppm

CO:
limit 1.08%
my car 1.02%

The amazing thing is I passed the CO part of it, and they must of thought my presilencer was a cat because they made no mention of it.

Luckily, I still have the cats that I took off a few months ago. Will convertors help my hydrocarbon levels, or do I need some TPS adjustment? I just replaced the o2 sensor with a Bosch unit.

Any other advice on how to pass? Hopefully the cats will fix it, but the guy said the CO was basically my gas mileage so I dunno if the problem is really the exhaust or the mixture. No mixture screw on '89-'91, right? So what oh what do I need to do???

Thanks
Joe

 

HOLY ****!!!!

thats the highest HC reading ive ever seen, although ive never inspected a car w/ not cats

and yes, put them on! thats your best shot at passing

 

Do you think you can pass emissions (without cheating) with just a cat, ie with no air pump?

Also many fuel system cleaners have a "guarantee" to pass emissions, and they're supposed to be used on a full tank of gas. I've been told to use em on like a 1/4-1/2 tank, and you should be set (assuming you have cats)

I think some places have emissions testing equipment that aren't test places, they'll you check before you go for the test,maybe Pep Boys.


Well anyone who knows any tricks, I'm also interested in getting rid of at least my Air Pump, maybe my cats if I can swing it.

 

The hydrocarbon reading is fuel that isn't completly burnt coming out the exhaust. I think the cats help that, but I'm not sure excactly what they do. Make sure though that your timing is set to factory specs, adjust your tps, replace your plugs, wires, and air filter, and if you can have the car put on a scope; you need complete combustion. You might also just be running too rich.

Then, give your car a good hard drive at high rpm just before going to DEQ.

 

First I would try to do what Im gonna do, since I pulled off my cats. I have just straight pipe all the way to my stock mufflers. Anyways, Im gonna get my car titled in Columbus, since Franklin county dosent require E-check. Problem solved. I think the only way you can do that is if you have family there or something. See if anyone in your family anywhere lives in a city that is echeck exempt-and use their address. If you cant do that maybe this will work. My 91 civic wouldnt pass for the life of it. So I put 4 bottles of rubbing alcohol from the drugstore in the tank on a 1/4 tank of gas, and redlined the **** out of it all the way to the emissions place. Passed no prob. Alcohol wont hurt your car at all, it burns super clean, therefore it will lower your numbers a lot. Dont be afraid to dump a lot of bottles into it, after you get it checked go filler up. Let me know what happened bro.

 

we have tested a bunch of rx7's with no cats over the years,
if you put a straight pipe on everything else stock you get about 1500-2000ppm hc at idle
if you take the air pump out it goes up to
3500-4000ppm hc at idle
a street port with the stock smog stuff
125-500ppm hc at idle

mike

 

Well first off, what cats do.

Catalytic comverters serve as a place for the remaining unburned hydrocarbons(basicly fuel) to react. They serve as a catalyst for the reaction. The 7 has alot of unburnt hucrocarbons for each cycle, so we have an air pump (not sure if other cars do to) that pumps air into the main cat so that the HCs will have O2 to react with.


If you actually want to pass an emissions test with no cats (I don't know what good an air pump would do with out a cat) I think the alcohal would be your best bet. To burn gas most effiecntly you should use 14.7 parts air to one part gas (something like that) Alcohol on the other hand would be much lower like 2 to 1 or 3 to 1 (guessing). So by diluting your gas with alcohol you force your engine to run lean (having more air then necessary) which will leave very little excess HCs. As far as worrying about detonation because you're running lean I believe that the alcohol also protects against that because of its different properties.


*******!!! I have never done this, and all this info is based purely on theory and chemistry and whatnot, not on experience. I have no plans of trying this. I would put much more stock in the advice of someone who has actually done this succesfully, especially if they did it with a rotary.

All and all I think you'd be better off trying to find a shop that you can bribe, Although I would be very interested in the results if you did try it.

 

i doubt you'll pass with no cats......but, throw in some GTP (guaranteed to pass) gas additive. its 1 bottle/per tank. i knew i need a new O2 sensor and plugs before i took my n/a for emissions last may, but i figured hell, just take it anyway. i failed the first time...but barely...i was only a tad over on the hydrocarbons. anyway...put in a bottle...came back a day later....and passed perfectly

i don't think this will resolve your situation....but that **** definately helps...or your money back hahaha

 

So basically my car is right in line with how a rotary should test with no cats?
Thanks thats what I wanted to hear

Now to drag that heavy exhaust out of the garage and slap it in there. . .

 

What up joe?? Hey, do you still have your stock airbox? If ya do, right before you go to the e-check, get your car nice and warmed up, fill up a ziplock baggie or two with ice and put them in your airbox and see how it goes... that e-check passing fluid u can buy would help out too. BUT when your HC's go down, your CO's and CO2's will go up ( HC + O2 -> H20 + CO2) idealistically; but since you don't get an exact stoichiometric reaction, it will be more like (HC + O2 -> HC + H20 + CO2 + CO) So in otherwords... ur prly screwed... hahaha another way to pass your e-check is the 50 method..... give him $50... ****... i wouldn't turn that down if i was him Anyways, Zach, Steve and I are meetin up at my fraternity tomorrow around 11-12 if u wanna stop by. Msg me if ur interested and i can give u directions to get here.

Lataz,

Aaron

 

I've never seen people go through such crap, all i need is an inspection sticker and if you are just nice to the people you give them $12 the give you the sticker and you give them the VIN#. If i ever had someone do all that... i'de...move.
Jeff

 

i just barely failed with a straight pipe exhaust (passed visual somehow though)... my hydrocarbons were a tad high... and i mean just a tad. do those gas additives work when u are running no cats?

 

How about.. um.... BOTH!!!!

 

I love Minnesota! No e-inspections!