I have not posted in months and prefer to keep it that way, but because of the forum and alot of money I passed my emissions so maybe someone can get something useful from this.

during the First test my car was backfiring horrible upon deceleration. My idle was stuck around 1200 RPM. My mechanice found the Idle control valve to be bad and replaced it.



Second test, car still backfired and with a brand spanken new idle control valve I got worse #'s.




Both of the above tests were with a vaccume hose unplugged so the car cannot boost.

I went later in the day after my 2nd test on the same day and this time I turned my water injection on at 1 PSI and left it so they can boost. I misplaced my paper so I will have to give you the #'s I remember. I dont remember my CO Numbers, but the hydrocarbos were in the area of 280 and 240 (for speed test1 and test2).

The numbers dropped from the 700's to the high 200's with just water injection. I'm a little skepticle of that, another reason may be because my car sat forever waiting for the first emission test of the day, so it may have been cold contributing to the high #'s, but again I dont know.

Ok, so My air pump had been tested, my car had been tested at IDLE and was super clean. I have a streetport, power FC and new highflow cat.

Test 4 below was with a OEM cat that had only 35,000 miles on it. I also put Denatured alcohol in the tank and ran 87 octain. A huge difference in hydro carbons, no longer a gross poluter but way high.




Im getting desperate at this point. I brought my car to ricks rotary performance www.ricksrotary.com for him to do some troubleshooting. I showed up un-announced, he knew that my registration was out so He took my car in to try and find the problem. He spent about 2 hours on the car checking various things (and swaping my highflow cat back on). The air pump was good, no obvious problems. he eventually found that at IDLE air was getting to the cat, but when the RPMS increase it stopped. After some investigating he found the ACV selenoid was bad (a $685 part and $180 labor). Rick only charged me an hour labor, which was cool. I elected to ghetto rig my ACV By-pass.

I took the car home and bought an ABS heater hose T and 5/8th inch heater hose. I took the small 3 inch hose off the airpump and routed a new heater hose from the airpump, under the car to my new highflow cat and sealed it all.


Went to the smog place for # 5 and this was my dissapointment:




So close, but no dice.

# 6 time I put denatured alcohol in my gas tank, about 1 gallon to a half tank and made it so it cant boost. My HC went up.




for test # 7 I bought a used stock cat with around 100,000 miles on it and set my water injection to come on at 1 psi of boost and my #'s changed. there was no denatured alcohol in the tank and had 91 octain.




There are many variables here, but from what I can tell the denatured alcohol did nothing. Also both times the vaccum hose were removed to keep it from boosting the #'s went up. I can tell my highflow cat works, because as soon as I got air to my cat the #'s dropped to a number that would pass emissions anywhere else except california, but with the new emissions test the highflow cat failed. I'm sure if I had my precat on I could have passed even with the highflow cat.

The power FC is in all cases was tuned exactly as the stock ECU until boost is hit then it gets richer than a pig.

lastly, the stock cat is about 2.5 times heavier than my highflow cat and much louder. I am amazed how quiet my car is with my highfow. Its a night and day difference, I would have thought the highflow cat would be more noisy, but its quiet.

BTW, I know alot of you have PM'd me as I found out when I logged back on.


thanks.

 

Wow, man...what a hassle! I was gonna say that this isn't the first time I have seen a car fail with a "high flow" cat.

Denatured alcohol also did nothing for me.

Sonny

 

Congratulations, man, I know how much that stressed you out.....

 

Thanks for letting me Vent to you over the last 2 weeks, it helped believe it or not.

You got to hear my car, its so loud now with the OEM cat.

 

My last emissions experience back in January was similarly rough, it took me 6 tries to pass but my learning experience was somewhat different than yours. I wish I had been able to keep all my failed emissions papers, they take them away from you after each test out here. Because of this I have no numbers, only remember the trends.

I found the stock cat to make absolutely no difference in numbers from my high flow cat. Not even a couple percent which really shocked me. The stock cat did feel like it robbed me of 20HP and made my exhaust alot quieter though.

Denatured Alcohol did make a difference for me. You need a very high ratio, like at least 25% alcohol. This alone dropped my emissions by approximately 50%. How much alcohol were you running?

I didnt use my water injection, most of my tests were done with a huge boost leak I put in a silicon coupler to limit me to 0, I should have left my car boost and run the water injection to see what kind of difference it made.

I ran with the PowerFC and also tried the stock ECU, I had better results with the PFC by about 10% running the base map.

 

I think different problems are affected differently by our choice of 'fixes'. If you're high on the CO and HC and you have a lot of leftover oxygen, typically it is the cat.

I was having a problem with NOx at 25mph. Denatured alcohol didn't work (about 20% concentration) for me. I had completely rebuilt this (piston -- *gasp* ) engine, so none of the parts were old/suspect. What ended up fixing it for me was more fuel. I simply stuck a plug in the FPR line. It pulled the fuel pressure up 10 psi and my NOx got chopped it half.

Sonny

 

Very nice write up I'm glad I don't have to go back for another 20 months. I can feel the ulcer coming on just reading your story.

 

i think if you're flagged as gross polluter you have to do it every year.

 

damn what a hassle, if anything I know a spot to pass of the inspection guy $60bux and he'll pass me without any hassle. He just takes the exhuast hose and put it on a regular car and runs my car on the lil emission dyno..

 

What about tuning the Power FC in the Inj fuel blocks that you are tested in? Taking away 5% to 15% fuel and running the car(just for the test) at appx. 14.xxx a/f won't hurt the engine. I have gone as high(not intentionally) as 15.xxx a/f and didn't have any stuttering...but at 18.xxx a/f the engine would bog and the car would run like freeze dried dog turd.

 

Not if you move away from the peoples republic of Kalifornia

 

i'm new to the rx7 world and have only had mine for a little while. it still needs to pass emissions and has a leak from the oil pan. the car is completely stock. do you have any suggestions on how to get my levels down? please, if i dont get it passed in two weeks my dad is going to force me to sell my recently purchased rx7...which would be a huge bummer.

 

I have had my stock cat on the car for 111,000 miles now and it has always had the airmpump feeding it...

With a streetport engine, DP, stock cat, racing beat exhaust, and PFC with base maps....I passed emissions EASILY!!!!! I did let the car sit and idle forever to make sure the cat was hot. Additionally, this is only with 100 miles on the new engine.

My hydrocarbon levels were super LOW!!! My suggestion is that if your stock cat is still good,, keep it around and swap it back on when inspection time rolls around.

I also just purchased the knightsport highflow cat with the metallit technology, I'll try to do a sniffer in the next week for a comparision.

 

Has anyone tried out ethyl alcohol on an RX-8 engine? I am curious since I plan on removing my cat.

 

Thanks for the write-up ZeroBanger....I'm going to purchase an RX-7 that I guess smokes like the space shuttle lifting off from Cape Canivaral.....I will try your suggestions. BTW, using water injection....is it safe?

 

dont forget to keep the secondary airline that feeds back to your stock cat too, i didnt even know that existed, but the smog inspection station sure noticed, and this was after i already passed smog.