hi

well i have noticed a few days after i got my coils/plugs and leads all changed that when car is warmed up and i am in 2nd and the revs are building up, there is a slight hesitation between 4000/5000 rpm and about 7000rpm, then the car is back to normal and accelerates normally up to 9000 rpm till the buzzer sounds.

i have no CEL's, got my scangauge II today, hooked it up and it says no error codes. car starts fine, drives fine at motorway speeds 70mph, and pulls fine through the gears etc, better than before due to new plugs.

i got my CAT changed about 10000 miles ago due to a fault it developed so dealership covered it as only had the car a few weeks.

when that happened the SS CAT back exhaust did not crackle as much. This time it just isn't as crackly but still does. I ran some CATACLEAN which cleans engines and CATS through the car, you pour it into your petrol(gas tank), gave it a good dose of 500ml per 15 litres of petrol(gas) like it states. I have used it before on my mx3 and it really improved the car, checked it was ok for rotary engines etc.

the delay improved, in that just not as bad. its only in 2nd really when keeping your foot down on the gas as the revs rise, car does not buck or anything, just feels like its not breathing right, then springs back to normal when in the higher revs.

has anyone experienced this before, i got the CAT about 14 months ago, and i think i was told a years warranty on it. now battery was low when mechanic changed plugs and she wouldn't start so had to tow start, smoke as expected out the back of the exhaust when she kicked into life but idled at 1000rpm and was perfect. the mechanic cleared the misfire error code and nothing since. did get a slight hesitation the next day in 2nd going up the revs. the next day the battery was low, got a jump from the breakdown guy and she fired into life, went for a spin round the car park and she felt good, no codes etc.

i did get a new battery as the one the car came with was not high enough for cranking. so i put the new battery on and started the car, again no problems, lovely note off the exhaust, went for a drive, pulled great no hesitation etc.

was very happy as everything looked great. now the note is not as good off the exhaust, as i gently rev no crackle only on higher revs. the odd time after a red line and when the car is parked while i open the yard gate, i hear the familar crackle, so i think the CAT is ok etc.

I did not fill up, as I want to give the additive time to clean the CAT more, just in case. I do not wanna fit another, and am getting no error codes to say its faulty or has got damaged. dunno if mechanic flooded the car trying to start it, but was driving fine after that.

would driving the car hard the odd time after a battery being installed and ecu reset cause this? i did put in a K&N air filter, no kit just the one that goes into the air box. could its oil be affecting the MAF?

any ideas welcome, i can't see why RX8 CATS fail so quickly and not getting any error codes on the scan gauge II. anyone know how to test the CAT with the scan gauge, any particular xgauge setting/the correct working temperature it should be? my 8 is a 231 6 speed.

thanks, quite worried at the moment as want my baby in top shape after spending £550.

hi

Well took the car out tonight to fill up, there was just a slight hesitation above the 5000 rpm, 6 then 7 limits in 2nd. car was driving ok, no codes coming up on scangaugeII it says I am getting about 24mpg from the saturday i have it in, for 6-10 mile journeys. on the way home after filling up with sainsburys supermarket 95octane low sulphur petrol, it wasn't as perky but drove ok.

I then tried a redline in 2nd driving up my lane to home and got the hesitation, followed by a buck, then went up to the red line, so i backed off. Car idles fine at the 1000 or 800 mark. I am not sure if the CAT got damaged when we had to tow start it, although it drove bloody great after, like new, pulled through the revs with no hesitation at all.
I also had the K&N air filter in before the coils went out, so dunno if MAF has been affected.

The more I read about similar power declines at higher rpms above 5000 rpm, the more I hear the CAT is bad or clogged, I would need to get my mechanic to inspect it. I am gonna go out now and push the leads etc down as best as I can just to make sure its not something silly.

The Mazda CATS £1100, are so expensive I have seen some on ebay made by specialists for £240 up to £370. Which I can live with, but do we have to use the Mazda make of CAT, it seems crap anyways and doesn't last long or can't take a coil/spark plug going out and not getting damaged by it.
Like I said I had mine replaced with a brand new Mazda rx8 one 10000 miles ago and if the coils burning out etc tow starting had damaged it, would it not have been crap as soon as I got the car going. The car was very quick after we started it about a week ago, this started to happen a few days after.

If it is the CAT, then would someone please tell me is there a better aftermarket CAT which would suit, now I will be buying probably from the UK, so need some company from around the UK, sorry american cousins but I don't think we have a 100000 mile warranty which emissions laws must make the car manufactor comply with. I didn't get offered anything the first time when it went at 62000 miles, just luckily a good will gesture by the dealership I bought the car from.

Can anyone help please. :(

Thanks