So I have done my searching and I haven't really found an exact answer to my problem. I bought a used MY09 manual with 30k miles on it. My CEL came on and I took it to a dealership to have them diagnose it. They said since there is a aftermarket exhaust on it (Not sure which one) which is the reason for tripping the error codes above. They confirmed that everything else on the car was fine. So here I am now trying to get my options on getting the CEL to turn off. They mentioned putting an o2 sim in the pipe but after researching I have concluded that there is not one available for the RX-8.

 

Tell us more about your car.

You said it's an '09 with 30k miles on it, and that you recently bought it.

How recently?
Did you buy it from a car dealer, or a private sale?
Is that a Canadian Market car?

How many miles did you own it before the CEL came on?

Here's your codes:

P0139 - Rear HO2S circuit slow response
P0420 - Catalyst system efficiency below threshold

I think you have the wrong code for the middle one.
Basically, your car is telling you that you don't have a catalytic convertor on your car.

Take your car back to where you bought it, and demand they provide you with the original exhaust system.

BC.

 

I bought it in May of this year.
Car Dealer.
I am unsure. I bought it in Seattle,WA and it already had WA plates on it.

I drove it about 100 miles before it came on. I just now had them look at it because I needed to wait 30 days before my extended warranty I purchased took effect.

Yeah, I already knew what the codes were before I posted this post. The seconded one I couldn't figure out as they might have written it down wrong for me. I posted it as they wrote it down on the chance someone might recognized it before I considered it a mistype on the paper.

Also I went and looked at the car and it has a Racing Beats exhaust system on it with aftermarket headers. I have included some pictures of it as well. Also when I had them look at it, they were already willing to remove the current system and replace it with stock under the warranty however they told me that it would reduce the performance so I told them I would hold off until I researched it more. Also there is a converter there.

 

Is that your car in your signature? It is a US car right?

Is it an R3 repainted white or a conversion? If it's a conversion, looks like they have all the pieces including the spoiler.

 

Yes it is my car, and for all I know it is a US car.

I believe it is an R3 according to this .

It has Bose audio, bluetooth and keyless entry. I am going to go take a quick look at the paperwork.

 

I just looked at the dealership paperwork and it does say R3 on it. It it a problem?

 

It's definitely been repainted, a lot of the black trim was painted over as well. That will be a PIA later. They did not make the R3 in white, in the US. But until we see the interior we cannot say for sure.

As for the codes, you will either have to put a stock cat on, or live with it. O2 simulators don't work on the RX-8. I do believe federal law requires the dealership to make this right, they cannot sell a car that does not pass emissions. It has nothing to do with the warranty.

 

It sounds like an R3, the only other model with advanced keyless entry was the Grand Tourings. They had Auto A/C too, but the R3s had manual A/C.

Can you see any of the original color like under the hood or jambs? Also your struts should be yellow Bilsteins unless they were swapped out. And of course you should have Recaro seats unless those were removed as well.

 

Just because there's a shell of a catalyst there doesn't mean there's anything inside it. Some people still think they'll get significant performance increases by hollowing out the catalyst, even though it's not the 1980's anymore and car manufacturers have figured out how to make high-flow catalysts now. Given the ghetto-fabulous paint job on the bodywork and the rims, I'd be willing to bet (a small amount of) money that the former owner hollowed the catalyst so The Man wouldn't keep stealing that extra 2 horsepower from them.

 

Here is some photos of the inside.

Is there anyway to just turn off the light then?

 

He posted a pic already, that's not the stock Cat.

 

That is an R3. There is no easy way to turn off the light.

 

As I mentioned before, it is there and I have already took it to the dealership and they could not find anything wrong with it. The only option they gave me was that they would replace the entire exhaust system, which at the moment I don't want to do until I have researched my car more.

 

Yeah, I saw. I'm still not used to the way this forum hosts pictures. I keep expecting to see full-size photos, not thumbnails, so I keep overlooking them.

I revised my post above.

 

I say R3 for sure! Congrats on the purchase and welcome!

Get them to get you a stock cat, that thing is like over $1500!

 

Honestly I doubt you'd notice anything besides a change in the exhaust sound if they replaced the entire system with OE stock.

Get it fixed under warranty, and ask them to put the aftermarket parts in the backseat. You can decide what to do with them later.

 

OP, Post or PM me your total VIN Number and I can tell what should be on your car...

However it makes no difference if it is an R3 or not, all exhausts and almost everything else is the same for 2009~ RX-8's (Series 2) on-wards.

And Yes, your Exhaust is not standard, it actually looks like no part of it is OEM, maybe exhaust Hangers and Manifold are, that is about all.

A Series 2 CAT starts from $2,215 -$2840 retail.

This is where you have to start, and you will need a new 02 Sensor for the CAT as it does not come with one, another $200+.

 

The Racing Beat cat-back (the muffler assembly) will not cause a CEL by itself and is a nice addition to the car, so keep that. RX8: Exhaust - Cat-Back Systems: REV8 Exhaust System - Single Tip - 09-11 RX-8 -

The stock cat is worth its weight in gold, so try to get it. In the 'lingo' it's called a mid-pipe. There are minimal gains to be had by getting rid of the stock one, especially since the 09+ model engine controls are not easily modified to match, plus the CEL will be forever on, hiding any other failures from your attention when they occur.

 

PM sent Ash8

I am going to go into the dealership next week and see about getting the CAT and the o2 sensor replaced. I want to keep the cat-back system so I guess I am going to have to do some sweet talking as they want to replace the entire exhaust system. I have a pretty good relationship with the dealer.

 

Good luck with it all...

Your VIN confirms you have an R3, but it was originally painted from factory in A3F Brilliant Black, not white.

 

Nice R3, I like what they did to the door panels.
wish Mazda would have offered the R3 in white in 2011 here in the U.S.

Can you post better pictures of the door panels please?

 

Long story short, from experience:
I have this Racing Beat Exhaust RX8: Exhaust - Cat-Back Systems: REV8 Exhaust System - Single Tip - 09-11 RX-8 -
And this CorkSport Race Pipe with HF cat CORKSPORT Power Series Racepipe For Rx8
I had the racepipe alone for almost a year. I was getting the P0420 until I replaced my O2 sensor, then no probs until I got the RB exhaust. I began throwing p0420s again, but only in the mountains. I tried a spacer for the sensor, but started getting the p0139.

As long as I don't drive hundreds of miles in the mountains I'm fine with my current combination using an O2 sensor that has less than 10kmi.

 

I think it has more to do with your driving than the 02 sensor. The PCM doesn't check the catalyst until you have a fully warmed up vehicle and you do a steady highway cruise. If your on and off the throttle a lot, it can't run the test.

So it sounds like when your driving in the mountains, it runs the test. Stop and go driving, it will never get a chance also. I believe the catalyst monitor is a two trip check too, therefore the PCM has to run the test twice and fail before it turns on the code & light.

The only sure way to check if this is happening is to see use a scan tool and see if the catalyst monitor has run and the results of the test.

 

Of course we're off on a tangent now, but...

The mountainous driving that showed the symptom wasn't twisties, it was "highwayish" driving. I was on a direct route through CA & NV. My car REALLY didn't like the elevation. The CEL only showed up in the mountains and only 2000+ feet. When I was above 4000ft I started to get concerned that I was having a real problem, but once I came down all was good.

I do immediatly check CELs on the road and clear as soon as convenient. I do watch the DCT statuses and can see that it takes a couple cycles for the O2 and a few drive cycles for the catalyst to compete their tests after a reset.

 

Even if the RX-8 doesn't have a wideband oxygen sensor, it can still check the catalyst's performance as long as the throttle is less than ~50% open. It only takes a minute or so to run the test twice; that's about how much time I've seen other cars take.