Evora spat out some pieces of cat

[Pedal_Loud]

Finished a track day a couple of weeks ago with and EML an a rattle. 
The next day all was fine with no EML and no rattle.  Until yesterday when the car threw an EML which this time I managed to read: P0420 and P1302 came up so a swapped over no.2 coil pack to see if I could get the error code to come back after clearing the error.
Right after this I found what I’m assuming is chunks of the catalytic converter on the drive (see pic). I’m guessing this is what was causing my track day rattle and eventually worked it’s way out and the cat is now slowly disintegrating. 
I’m just hoping this is from the third cat near the main muffler in which case seems like a good time to replace with a straight pipe from 2bular.

Does this sound likely? Car is popping a lot more in non-sport mode which I’m guessing is as a result of having less bits of cat in there! 
My worry is the 2 x main pre-cats are also shot but these cat bits have to be from the after cat surely? My course of action is to fit the cat bypass (how easy it? is there a DIY anywhere?) and then wait to see if the pre-cats throw a code....

 

[Ledlights]

I don’t think these cars consume the manifold cats like the old MR2s did, so I think it’s more likely that it’s the 3rd cat that’s given up the ghost (assuming you’ve got one).  However, the DTCs could indicate a problem with the bank 1 cat, so to be on the safe side I’d  probably drop the headers and have a look with a borescope to make sure. There’s a guide on how to do this on lotustalk which I’ve copied here in previous posts.

Hope this helps,

Steve

Edited March 10, 2019 by Ledlights

[Pedal_Loud]

So, I did some measuring with my OBD software this weekend on all 4 O2 sensors to see if the main cats are bad.

Looks like the cat on bank 1 is not functioning as it should (pics attached), whereas bank 2 looks ok.

Long term my strategy is to get new headers with sports cats and possibly a Larini or 2bular exhaust. However, current finances just don't allow for that so in the interim I intend to work a short term tactical repair on the bank 1 cat (not sure what that is yet!). The third cat I'm just removing having already ordered a straight pipe.

Couple of questions though... My initial error codes indicated a misfire fault on cylinder 2 (P1302) which is on bank 2, yet from the data it would seem to indicate the cat is shot on bank 1. Any ideas why that might be?

Also, I've attached a pic of the banks, cylinder numbers based on the position of the engine in the car - is this correct? My understanding is the back 1 header/cat is at the rear of the car and should be pretty easy to swap out.

 

 

[#84]

I cannot confirm the cylinder/bank numbering, or explain why you got misfire on cylinder two on a V-engine with this fault, but:

I have had the rattle, pieces coming out of the main cat and in that case it was the pre-cat from cylinder bank one that had melted and then damaged the main cat. However, the rattling sound came from a broken piston (ringland collapse). Probably the pre-cat broke first and killed the piston with its back pressure, but it could have been the other way around. Let's hope this is not the case, but you have to remove that manifold and check the pre-cat. If you don't have the budget for 2-Bular/Larini/etc the simplest way around is to fit a new standard manifold. If you replace the main cat with a straight pipe, there is no easy fix to do the same with the pre-cat and avoid error codes.

If you look for a cheap original manifold and don't find one in your area, I believe I have a new one - used 1 hour. 

BTW - which is the app you used to get the oscilloscope function?

[Pedal_Loud]

Thanks, I've procured a set of second hand pre-cats from a 2015 car and a straight pipe to replace the 3rd cat. I know this isn't the best solution but for now it works for me at this time. A new standard manifold x 2 isn't much different from a larini or 2bular.

I'm hoping no bits of cat have made their way into the engine but there are no obvious signs.

So this weekend it'll be time to start work on getting the headers off and hopefully getting the new second hand ones on!

I used https://www.obdautodoctor.com for the OBD2 graph. Very handy to confirm a diagnosis like this.

[Ledlights]

Good luck this, the guide below might help:

https://www.lotustalk.com/forums/f417/complete-larini-header-exhaust-diy-322593/

Steve

[Pedal_Loud]

8 hours ago, Ledlights said:

Good luck this, the guide below might help:

https://www.lotustalk.com/forums/f417/complete-larini-header-exhaust-diy-322593/

Steve

Yes - if it wasn't for that awesome post I don't think I'd be trying it! New secondhand cats arrived today and they look like new inside so hopefully lots more life left in them!

Edited March 21, 2019 by Pedal_Loud

[Pedal_Loud]

Went in today to remove the bank 1 cat. Managed to do it after much swearing and negotiation. Dare I say it wasn't quite a simple at the larini exhaust guide made out for various reasons.

Anyway the news is the bank 1 cat was non-existent. There was no honeycomb left in there whatsoever. I just hope it all exited out the tailpipe!

The bank 2 cat looks in fine condition. So even though I have a spare I don't think I'm going to tackle that one for now.

I was also able to see that I already have a straight pipe where the 3rd cat should be.

All in all a pretty good day of discovery and removal. I need to order a few more bolts then screw everything back together. Reckon I've saved a fair bit on cash by used cats and doing the work myself!

Edited March 23, 2019 by Pedal_Loud

[ramjet]

Make sure you get the rest of the cat out of the car.

It'll leave a stain as it keeps decaying. I presume, since you said little bits, that maybe just the paws and some ears? Maybe the tail? Head and body may still be in the car?  

[Pedal_Loud]

🤣

[Mark030358]

Go buy a set of 2bular manifolds, down pipes and CAT. 

Just my 2p worth, you can read about CAT failures on his site.

cheers

[Pedal_Loud]

On 23/03/2019 at 21:41, Mark030358 said:

Go buy a set of 2bular manifolds, down pipes and CAT. 

Just my 2p worth, you can read about CAT failures on his site.

cheers

Yeh I will at some point. This is a temporary albeit slightly riskier short term fix.

[Mark030358]

7 hours ago, Pedal_Loud said:

Yeh I will at some point. This is a temporary albeit slightly riskier short term fix.

Hope all goes well mate...👍👍