Mazda RX8 advice

[TIMONLINE]

I have an RX8 which has failed emissions on carbon monoxide and hydrocarbons.

Any suggestions on what might be the cause? I'm guessing that carbon monoxide issues are due to a failed cat.

[lincsls2]

I've read that a bottle of CATACLEAN does wonders for bringing down emissions.

http://www.ebay.co.uk/sch/i.html?_trksid=p2050601....

Need to add full bottle to around 15 litres of fuel, so quite concentrated.
I've used it on the wife's RX8 prior to the MOT and its always been very clean although I know it might not be anything to do with the additive.
Worth a try, supposed to be very good...

[PhillipM]

Dead cat, but check all the coils, leads and plugs because they're the usual cause of a dead cat converter. Double check the oil hasn't been overfilled too.

[SystemParanoia]

time to fit an LS motor

[NotLynch]

A lot of RX-8s fail emissions because the cat/engine is cold during the test; at least it seems to be common on the OC, mine passed first time so I don't have any experience myself. If you get it tested again without changing the cat make sure it's screaming hot when the test is done.

[22Rgt]

|Time to scrap it as repair is most likely more than its worth.Worn out at 60K miles, has to be one of the most fragile engines ever made , the only one ever produced from semi hardened chocolate..

[ShaunTheSheep]

PhillipM said:

Dead cat, but check all the coils, leads and plugs because they're the usual cause of a dead cat converter. Double check the oil hasn't been overfilled too.

Yeah definitely this. If you don't fix the cause and only repair the symptom, youll need another cat in no time.

When were your coils last replaced? Should be every 30k I think.

[TIMONLINE]

Coils were replaced 2.5 years ago along with the cat and since then I've only done 9.5K miles.

I'm pretty sure the cat is shot as the exhaust (cat?) is rattling.

I understand that a couple of rotor tips are worn which could be causing the hydrocarbon emissions failure?

[otolith]

Knackered cat will be enough to screw the emissions. I'd get a compression test and if that is good, replace the cat and the coil pack.

[TIMONLINE]

How to get a compression test though?!

[otolith]

Take it to a Mazda dealer or rotary specialist and ask for one.

[nottyash]

Do you have trouble starting it when hot too?

[wolves_wanderer]

TIMONLINE said:

Coils were replaced 2.5 years ago along with the cat and since then I've only done 9.5K miles.

I'm pretty sure the cat is shot as the exhaust (cat?) is rattling.

I understand that a couple of rotor tips are worn which could be causing the hydrocarbon emissions failure?

Exhaust rattling is definitely the cat.