Emissions Help

[JZstl]

Hello all,

I'm new to the Mazda community and I wanted to ask for some local knowledge about getting my new RX-8 to pass emissions. I did quite a bit of reading on RX-8club.com and I found a few articles that were helpful, but I wanted to see what has worked best for Colorado in particular.

So I bought my RX-8 a couple weeks ago off Craigslist and I'm excited to get to know these cars better. I have owned several sporty cars in the past, but I have always liked RX-8s and this one was seemed to be a good value. It is on its second engine and has about 27k on the new engine. When I went for the test drive, I could smell/tell it was running a bit rich, as there was the smell of unburnt fuel out of the exhaust. After talking with the seller and telling him that he would be responsible if it didn't pass emissions, he decided to drop the price further in exchange for me no longer holding him responsible. Whether that was a good or bad idea is another topic, but anyway, that's the situation I'm in.

So I failed emissions this week, as I suspected, and after doing reading, I'm betting it is the catalytic converter. What do you guys think is the best plan to get it passing emissions? I have read around that the oem catalytic converters are the best ones out there, but they are a little over $1000 new, right? I also know you can't find them in junkyards, but sometimes people sell used ones on forums, etc. Or there are cheaper ones that will not last long at all. What has worked for you all?

Also, should I mess around with any of the other things that might make it fail emissions - O2 sensors, plugs, coils, etc.? I was planning on doing this list of preventative maintenance stuff eventually (http://www.rx8club.com/new-member-forum-197/new-potential-owners-start-here-202454/), but I would at least like to get it legal first.

Thank you all in advance - in doing some reading it looks like there are some really smart rotary fans on here! Oh, and if anyone wants to meet up and see it in person - I'm located in Parker.
John

[Brigdh]

This is pretty much why Colorado state law requires the seller to provide proof of emissions compliance (a passing emissions test report) when selling to someone who lives an emissions controlled county. That way, you don't get stuck fixing some emissions issue which usually means $$$$ and until its fixed, you are usually racking up non-registration fees.

Of course, it sounds like you are past that.

What were the results of the test? Specifically the HC, CO, NOX readings vs the permitted levels. Do you have a CEL? Have you pulled the codes?

If I were to guess, whatever caused the original engine to fail started damaging the cat, however I would investigate further before throwing parts at the car. Its entirely possible you don't actually need a new cat, and something else is wrong.

On the subject of cats, the rotary has different emissions control needs when comparing to a piston engine. OEM is best. The only aftermarket cat that I know of that will last in a rotary application is a Bonez cat from rx7.com. Any other aftermarket cat is built to piston engine standards, and depending on its quality, may not work well enough to pass the emission test. Assuming it does work well enough to pass, its unlikely the cat will last long and you will likely be replacing it frequently.

Also, what year RX-8? Emissions components are required by federal law to be warrantied for 8 years, 80k miles, whichever comes first. If you have a new enough RX-8, you may still be under warranty.

[RXMiles]

You bought the car in a "As is" basis, so you can't hold the PO accountable if it was private party. That being said your car is fairly recent to have a problem with the cat unless your OMP is metering to much oil. If you can post a picture of the emissions report this will help us tremendously. About a year ago, before acquiring the Turbo II I bought a S5 GTU that had sat for years in this guys driveway, anyways it passed with flying colors.

[JZstl]

Thank you both for your replies - sorry for my delay - super busy teaching and coaching. I was aware of the deal with the seller providing emissions, but after letting the seller know, he just decided to knock off another chunk of cash and he cleared himself. I needed a car, and it was a good car for the money.

As far as the details for the test, of course my dog chewed up the exact #s, but they were very similar to the #s I read in another forum. It failed in all 3 categories, but it passed the check engine light test. It was close to 5 for hc , co was somewhere around 5?, and co2 was around 4. There are some engine warning lights, but they go off and on - the previous owner said this was due to the engine being replaced...

Good call on not just going for the cat - I was speculating it is the cat, but I didn't know if everyone would be certain it is the cat. Good to know on aftermarkets - I will try to find an OEM one for sure if it is the cat. Theoretically, do you guys think it is worth looking into a slightly used one (since some places that don't have emissions, people take them off all the time, right?) or do you think you pretty much need to pony up for an expensive new OEM one?

My RX-8 is a 2004 - unfortunately no warranty left.

Anyone potentially available to help look at my RX-8? I'm cool with driving to you if you would like, and I'm cool with buying beer or throwing some $ your way. I suppose I could take it to a shop, but from what I have read and experienced with other cars, it is better to work with enthusiasts on forums who actually know the specific car that needs the work - imo.

Thanks, John

[Shadowden]

Aren't there a bunch of "tricks" that were posted to get the rotary engines to pass? Like running them really hot, running some e85, and some other stuff?

Sorry can't help specifically, but i do recall such a post. I know Walker contributed to that as well as many others.

Here is a thread on emissions. Potentially differnt, but pull what you can: http://www.coloradomazdaclub.com/forums/showthread.php?t=8540

[JZstl]

I did both of those tricks for my Eclipse GSX, and I was eventually able to get it to pass. My GSX was running rich when I bought it, and after I got it tuned I didn't have the engine as warm as I should have, and it barely failed. The next day I ran it around with some passes on full boost and I put in a gallon of E85 to mix with my premium, and it passed by a good margin.

I wasn't sure if those tricks would be 100% applicable for rotarys too. I did have the engine fully warmed up, when I tested, but no luck. It doesn't smoke or anything, but you can for sure smell that there is unburnt fuel.

I know there are mixed opinions on this stuff, is there a chance that something like Sea Foam would help?

Thanks for the input - doesn't hurt right?

[Brigdh]

Thank you both for your replies - sorry for my delay - super busy teaching and coaching. I was aware of the deal with the seller providing emissions, but after letting the seller know, he just decided to knock off another chunk of cash and he cleared himself. I needed a car, and it was a good car for the money.

As far as the details for the test, of course my dog chewed up the exact #s, but they were very similar to the #s I read in another forum. It failed in all 3 categories, but it passed the check engine light test. It was close to 5 for hc , co was somewhere around 5?, and co2 was around 4. There are some engine warning lights, but they go off and on - the previous owner said this was due to the engine being replaced...

Good call on not just going for the cat - I was speculating it is the cat, but I didn't know if everyone would be certain it is the cat. Good to know on aftermarkets - I will try to find an OEM one for sure if it is the cat. Theoretically, do you guys think it is worth looking into a slightly used one (since some places that don't have emissions, people take them off all the time, right?) or do you think you pretty much need to pony up for an expensive new OEM one?

My RX-8 is a 2004 - unfortunately no warranty left.

Anyone potentially available to help look at my RX-8? I'm cool with driving to you if you would like, and I'm cool with buying beer or throwing some $ your way. I suppose I could take it to a shop, but from what I have read and experienced with other cars, it is better to work with enthusiasts on forums who actually know the specific car that needs the work - imo.

Thanks, John

The check engine light test on an emissions test report means nothing. If they can't plug into the computer, they skip it and you "pass".

What engine warning lights come on and off? You mean the CEL blinks? If the CEL is blinking, you have misfires, which is really not good. A replaced engine should not be misfiring. In fact, no warning lights should be coming on "because its a replaced engine". Any chance you can take a video?

[millertime]

Start with changing plugs and wires and see where that gets you. If you're getting misfires it's a quick way to potentially clear that up.

[Brigdh]

So, I dug up my most recient emissions report for my '06 RX-8.

HC was 0.0657, limit is 1.2
CO was 4.4585, limit is 15
CO2 was 442.7727, no limit
NOx was 0.1308, limit is 1.5

So, you thought HC was 5, thats clearly "high". You thought CO was around 5, which sounds like avergage. You thought CO2 was around 4, which I suspect was really your NOx reading (since CO2 at 4 is kind of impossibly low), so thats also high.

I've used this as a guide line in the past: http://www.rx7club.com/2nd-generation-specific-1986-1992-17/frequently-asked-questions-2nd-generation-rx-7-faq-fc-494667/#post5131106 It suggests looking at the cat, among other things for your situation.

I would probably change plugs, spark plug wires, and coils right off the bat. I would also drop the cat and make a visual inspection to see how it looks. I would also pull the codes, even if you don't have a CEL right now, since I suspect you probably have some stored codes. Your local auto parts store like Advance will do that for free.

You probably need a new cat, but the important thing is to find the issue and address it, otherwise you'll just end up destroying the new cat.

[GR-8]

Hey Yo. I really can't think of anything or tricks to get the RX-8s to pass right now. I have never had that problem with my 2 RX-8's passing emissions. When I take them in they both have a magnaflow muffler, intake, and the stock cats. Both have 54-60k miles on them and both '04. Are all the emissions equipment in place. Any aftermarket parts. Connection to the air pump? I'd be happy to poke around a bit. Maybe start with something simple and make sure the spark plugs are good, possibly the MAF sensor could be dirty and in turn is causing it to run rich.

I'm willing to take a look around. Not sure how much help I'd be. I live in Denver, work till 3-4 everyday so has to be a evening deal. In my Bronco I run the tank to about 1/8 full and throw in a gallon of "De-Natured Alcohol". I wouldn't recommend doing that on a rotary though. If needed I have the stock cat off my turbo 8 and you could borrow it to make a pass at the testing center see if you pass.

[D Walker]

I can maybe help you next week, but it would have to be sometime next week, after taht we are gone a lot.

[RXMiles]

I'm glad to help as well, however I can. You need to address the underlying problem to the emissions situation. Do you really want to add E85 to your car just to pass the sniffer, or have a properly working car? Leave the cat to the very end as you might not need it. There's no circumventing a clean running car.

I would start out by checking your ignition, it sounds like the place to start given the misfire. Do plugs and wires to rue those out and upload pictures as it could help with seeing how the engine is burning fuel. Now I am not at all familiar with the renessis but there is something simple, I am sure that;s making you run dirty.

[speedjunkie]

Or you can do the easiest thing and register it in another county, one that doesn't have emissions...like El Paso county.

And no, it's not illegal lol.

[RXMiles]

Or you can do the easiest thing and register it in another county, one that doesn't have emissions...like El Paso county.

And no, it's not illegal lol.

I don't think you can do that anymore. As far as I know you must reside in the county in order to register now.

[JZstl]

So I'm available for most of the day tomorrow, or I could do a Sunday too. I would love to meet up and have someone give me a hand. I read in a couple different forums that plugs and wires are a good place to start as well, and for sure I would love to take a good look at the cat. Since a few people offered, anyone want to just name a time and place to get a few of us together? Just name your brew of choice. Thanks for the feedback all!

I would love to register the vehicle in a different county if it is legal (my wife's family owns a cabin in the mountains...), though I still want to get the car running properly. I would like the car to pass emissions in the next week or two, even if that means borrowing a cat (thanks for the offer GR-8). In the long run, certainly I would like to get everything figured out so that it will pass on its own and be running as well as it can. Several people mentioned a potential misfire, but it is running super smooth (high idle for the first minute or two, but it settles right down to 750ish rpm shortly), so I doubt it is misfiring, though I admit I'm no rotary expert.

If anyone wants to text/call options to meet for the weekend, feel free (618) 920-1924 - I'm from Illinois originally, local now.
Thanks, John