I have a 2010 GT all stock that just hit 10,000 miles.. for the last month, it has developed a quacking noise from the exhaust like a duck is stuck inside of it, right when I hit it hard at 8500-9000+. Occasionally it sounds like clumps of something are hitting the underside of my car too.. like i drove off with dried mud stuck to my wheels. No CEL, no power loss, just the annoying exhaust note.. also it doesnt always do it, but does 8 of 10 drives. I drive it hard (red line 1x on the way to work getting on interstate, and take the back roads home and red line it 4-5 times or more)... daily. A day ago, I noticed when I am flooring it up to redline, the power dips at 7000-8000 rpm, like the fuel was cut for 1/2 a second.. it recovers and again no CEL. That power loss started to worry me, so I took her into the dealer today for an oil change and had them look at it. The dealer ran diags on the cat and said it was performing well within range, and the sound im hearing is because im pushing the car so hard, its having a hard time "dealing with all the pressure from the high rpms.. when you run the car over 7k rpm this is going to happen and the cat is going to get hot and glow". Basically he told me this is normal. The dealer said they tested the coils/ignition system and there was no problem. I told them this is my 2nd rx8, I had a 2004 I drove to 60k miles before, had the cat on the 04 replaced around 30k but i had severe power loss after 6krpm and a CEL steady/flashing/misfires. Today dealer of course said this is a series II and things are "very different". Since the car is running fine other than the occasional drop in power and annoying duck stuck in my exhaust, i brought it home and thought id reach out to the community before getting into an arguement.

Should I have another dealer look at it, or will they probably just do the same with a pass on the cat diag? I figure if its the cat, it will eventually melt/crumble and then flag a CEL and they will then have to change it. I have plenty of warranty left to let it do that, Id just like to fix it now. The dealer said they reproduced the quack, and saw the hot cat, but did not feel a drop in power. I just noticed that yesterday, so not sure how often that will occur. I fig the cat is getting worse, if thats even the prob.

Thanks for any help.. I have another dealer around the corner from my office that I got my 04 serviced at while I had it for five years. I didnt want to waste my time if they are prob gonna say its functioning so let it go.

Jason

 

Take it to the other dealer.
Another person had to have the cat replaced on his R3 recently.

BC.

 

OE CATS are different for Series 2 and 55% more expensive than S1.
Sorry can't offer anymore assistance..I would perhaps wait and see?

 

This is one of the major reasons I went with a midpipe. Most dealers wont even check your cat unless there is a cel on. They just check for the cel, regardless of what you say is wrong and if its not there they say the cat is fine.

 

isnt the power dip caused by the "SSV" opening the intake port for power passed the 7000 rpm mark?, I regularly feel that dip on my r3, Ive learnd so far that its a port opening so you can have full power passed a certain rpm, glowing cat is normal, its operating temp is around 300oC.

for the power dip I just learned to drive it releasing the gaz to ajust around that rpm range and I dont feel it a all, at lease makes it feel normal

 

I don't have an S2 but glowing cat and power loss at higher rpm, you may have a clogged cat. Also a clogged cat may not even cause a CEL, it has to at least produce 1.5 times the normal pollution levels to cause a CEL. The cat maybe still working but, the collapse veins will block exhaust flow, thus power loss under load in the higher rpm.

 

This guy, right here. But I had a CEL along with mine.

 

The power dip at high RPM is normal. It feels like the car is about to run out of power, and then...it doesn't. Just a side effect of the variable intake system.

How do you know the catalyst is glowing?

 

Just Letting you know fix it fast, my dealership tech told me my cat took a dump and then my engine went KA-BOOM cause not enough air was going out and got backed up fast, So take care of it quick and you shouldn't be driving it. This is only if your having catalytic converter problems.

 

Any of you guys have an OBD2 type gauge like scangauge or something? When I use mine and look at the "Cat temp" it's usually around 800 celcius but can go over 900C during hard accel.

 

Mine only shows me the temp when a cel pops on, but the last reading was a little over 1600 degrees(F) on the highway doing ~70 mph. So yea that sounds about right. Not sure what difference a midpipe would make but I assume it would be cooler than a cat since there is less restriction? Maybe it changes nothing.