Glowing cat after 3-5min run time

[rogerts]

Hey guys

I’ve owned my rx8 for a good 7 years now, always had a second car for a few reasons, still think it’s a great car but could do with some advice..
Just over 2 and half years ago I got the cat changed emissions under threshold... then took it back the day after because it sounded like there was a clamp or something sliding up and down the exhaust, they said it was part of my old cat shouldn’t be much of an issue but if I wanted to remove it they would want to change the rest of the exhaust as quite rusty.
Obviously I did mean to get round to it but one thing or another got in the way. I have only put 4/5000 miles on it in the 2 half years then the ecu light came on again with the same code P0420 so spoke to the garage and a few other people about it was due to take it in for them to do an emissions test and see if the o2 sensors are working etc then went to go to the shop yesterday and while reversing out the drive noticed the car sounds weird and juddery so put it back on the drive that’s slightly raised and it took more effort to get it there than normal so turned it off and as I went to go back inside the house I noticed a bit of a glow so went to have a look under it and yeah I’ve not seen anything like that before. Will post a pic when I work out how to

[nightfire10]

Don't drive it till you've removed the obstruction and checked that the cat isn't blocked as well or you will kill the engine!

Sent from my FIG-LX1 using Tapatalk

[HarSc]

It is quite a common symptom for a cat glowing to be blocked. Saying that you've had it replaced, if it was a cheap special from ECP or the likes, 8's seem to melt through those within two years or less, as seems to be in line with what you've said... P0420 is cat efficiency, so in my eyes, cat is blocked/a gonner... Worth a check and i'm sure someone else on here will give their two cents too Definitely look at getting it replaced.

[rogerts]

Hmm can’t work out why I can’t post a pic probs because I’m just a guest.
Yeah that’s what I thought but knew I should definitely not drive it again.
Yeah not quite a cheap ECP job but a company called Chester exhaust specialist (direct rather than a small CES branch).

Do you think it could have something also to do with the fuel supply?
Any suggestions as what to get? Cost is a factor as as much as I love the car it can’t be worth much now (but is a kuro so worth saving) was planning on doing the a coil pack this year anyway.

What’s your views on second hand from after the cat incase it’s blocked further down to keep costs down worth it or not? (Obviously will depend on the actual unit) or is something cheap but new going to be better?

[New Duke]

You can get a brand new Toyosport decat for £100 delivered. How's about getting one of those. Then you'll rule out it being anything else too.

[rogerts]

Wouldn’t a de cat make it fail on emissions on next mot?

[chriskirkham]

Yes a decat will fail emissions test, but they sound good & the rotary engine will run better.

You could buy a cheap ECP cat and just swap it over each year for the test (use cataclean & make sure engine is properly up to temperature before they test).

Or buy a 200-cell sports cat, which will pass the test for a few years and will be less restrictive than a standard cat, plus they sound good.

The rest of the ignition system (coils, leads & plugs) need to be quality items to make a cat last and also to maintain a healthy engine, go cheap for exhaust parts if you must, but do not cheap out on ignition system.

Hope it helps, a Kuro is definately worth preserving.

Sent from my SM-T550 using Tapatalk

[BigPete]

Poor ignition will also cause this, un burnt fuel will kill the cat

[rogerts]

Thanks for all your time, been lost trawling google/YouTube/ eBay and such...
Dont know where to start, but definitely thinking the same as you Chris I don’t want to get cheap ignition parts not sure if it’s worth spending more to get upgraded ones now, probably should have a few years ago but... I was only planning on keeping the rx8 for 1 year max (mainly others scaremongering the bad rep) think that was in 2014 when I brought it, and whenever I contemplate changing it I can’t help but think is it worth me giving someone 8k plus my rx8 for a Toyota gt86 for e.g and in my mind no.

I’m not too sure about getting a decat and changing it every year, my diy experience consists of bulbs and air filters.. although looking at YouTube it does seem pretty simple to do a coil pack and thought exhausts have more welding involved than what it seems...

One thing that would be really handy if anyone could point me in the direction of a cheap diagnostic machine(if there is one) that can give me a readout in voltage for the o2 sensor? I got a cheap £20 job from eBay when I got the car just as a steer more than anything, didn’t think it would give me as just info as it does but only has an ok reading for the sensor...

[qwakers]

a elm 327 adaptor, a laptop and forscan.

[rogerts]

Hi guys, sorry to be annoying but does anyone know where to get a 200 cell cat fairly local to Bedfordshire? Also I noticed a few people say they smell? How bad? If there anyone local I can meet and see why you mean please?

[YORKSHIRE777]

Regarding smells...

- a decatted car smells of old skool exhaust, which some people fine eye-watering.
- a new cat often smells like rotten eggs for the first few drive cycles, whether on a new car or a new cat on an old car. This is just the initial chemical reaction and goes away the more the car is driven.

[nightfire10]

I've got a 200cel and don't notice it

Sent from my FIG-LX1 using Tapatalk

[rogerts]

Oh ok I’m not after a decat sorry a 200cell high flow that someone mentioned further up I think I might have got it mixed up then lol.

Unfortunately the one is still not in stock. I’ve tried calling the 0844 number on toyo website to see when it would be back it stock but it just rings out, what’s up with that?

There seems to be 2 options for ones under 300 japspeed or gravity so will go with the japspeed, is it worth going direct or on eBay as they seem to be a little cheaper?

[Nickp47]

They’re all the same product sold under different names. Buy through eBay, tends to be cheapest especially when the deals are on.
Re smell, you do get a little bit still, particularly whilst the car is warming up but it’s not the ‘tears to your eyes’ type fumes you get from a decat.

[350matt]

or you could pay a bit more and get a ryan rotary item as thats good quality and will last

[bigpete8]

Don't rotary revs also do an OEM style cat...
http://rotaryrevs.com/store/#engine

[rogerts]

Hi sorry someone said further up to get a high flow cat not another oem style ended up going for the japspeed one from eBay after giving japspeed a quick call to make sure it’s them lol anyway eBay had a discount code and I got 20% off so only cost £220 in case anyone is in same boat

[Koren]

That seems pretty reasonable! I got an ultra cheap one last year, so maybe I'll grab one of those too for when the cheapo one inevitably fails!