Have been getting the eml coming on a few times recently and getting a P0430 code cat system below threshold efficiency on bank 2.I thought it was a sensor on the way out until yesterday i noticed a good rattle coming from under the passenger side of the car.On further investigation there seems to be vibration in the exhaust.I believe this to be the cat starting to fail.Does anyone in the UK know if a good source for direct replacement cats.Also after reading some posts on the forum is it worth changing to 200 cell cats.Any info would be gratefully received.

Cheers
Steve.

 

If the cat itself is rattling that means it's broken up internally and needs to be replaced.

 

Yes I realise I need to replace both cats but I've done some searches and they seem quite difficult to get hold of.I shall be contacting an exhaust fabrication shop on Monday to see about replacing both cats and a full stainless steel exhaust system.Better get some overtime in to pay for it now lol.

 

No you probably don't need to replace both cats. Your exhaust system is stainless so don't waste your money putting in a full exhaust system. Replace the one cat that failed with a quality part and save your money.

 

Right guys need a little bit of help here.Cat from Jag is £830.00 or I can get two custom made cats and a complete x pipe system for just over a grand. I took the car to the exhaust shop today and the problem is the original cats are two compartment thats why they have two sensors the replacement cats are single compartment.They can make them but they say the eml will probably keep coming on.For those that have had custom cats is this the case or do I have nothing to worry about.I have the JLR software so getting rid of the eml will be no problem.The cats would be 400 cell.If I replace with a genuine cat, in the near future I will have to replace the other cat and exhaust system any way.Decisions decisions.

 

Im running 100 cell cats

O2 sensors are mounted using welded in bungs.
Just make sure the upstream and downstream sensors are about the same distance from the cat as before and you will be ok.

IF the exhaust shop did not know this may be an indicator to look elsewhere as its something they would be doing on a daily basis

PS If you have a lower cell rated cat you may need to fit a spacer,minicat or disable the downstram sensors.

Cheers
34by151

 

The MIL on would be an MoT fail.

I'd try a different place - one that has more of a clue.

 

Thanks for the replies.I will be contacting another couple of exhaust shops today to see what they say.

Cheers Steve.

 

i have 200cell magna flow cats installed these are only single chamber !
$800nzd fitted with 2.5'' pipe and x pipe .with welded in bosses .
i have had no issues with MIL,s or codes . they work perfectly.
i should mention it does raise the volume a little .

 

Great to know.Great picture as well thanks for the reply.

Cheers Steve.

 

I am also running 200 cel cats and no error codes.

Bought them from Paramount in the UK as they were the only ones I could find that "bolt in" without welding so I can go back to original if need to.

I tried using the "mini cats" that were supplied to push the O2 sensors out but they caused a problem. Screwed the O2 sensors in without the "mini cats" and no problems at all.

 

I have the 200 cells in mine.
No codes for the first month, but now constantly get 'catalyst inefficiency' codes. Has happened to everyone I have spoken to who has done this in the UK.

 

interesting . mine have been on for around 9 months , 4000km ish .
haven' t had one mil, for cat converters that is
sure hope i stay lucky .

 

The primary function of the downstream 02 sensor is to monitor the cat
The ECU compares the upstream and downstream to work out the cat efficiency.
My going to a 200 cell you have lowered the efficiency.
If everything else is perfect its not enough to trigger a MIL light.
As soon as you get something that causes you to run a little richer you will get the MIL.

That being said if you went 100 cell, as I have it will trigger regardless

To fix the issue you have 3 options

1. Fit spacers to the downstream O2 sensors. This is the worst option and may not work all the time but its the cheapest.
2. Fit minicats. These fit like the spacers but have cat mesh inside. The result is the mill will never trigger as sensor is behind a second set of cats.
3. Disable the O2 sensors. To do this the ECU needs to be reprogrammed. C
contact cambo if you want this done.


You can see my 100 cell cats + minicats as fitted in 2013, exhaust has changed since then though

Exhaust Manafold 4.2 S/C

Cheers
34by151

 

Quick update. Two new cats fitted with mini cats for the sensors,full x-pipe system all now sorted and sounding superb.

 

Can you list the parts you used. Mini cats brand and model. Same for the main cats and where they placed the O2 sensors.

Thanks,

 

I had the following exhaust upgrades installed:
MagnaFlow Catalytic Converters - Universal-Fit (59975) $90each
Magnaflow 10790 Tru-X Stainless Steel 2.25" pipe $80
Install with both resonators deleted, 4 bungs included $330.

No codes, but had to have a seam on the X-pipe welded as it split.

 

Unlike most systems, the downstream sensors on the Jags actually also trims the fuelling so it is important that these remain in the exhaust flow and not put into bosses or behind minicats as doing this will result in over fuelling (I know as this is what I did initially).


I run the 200 cell sport cats in mine and the car drove much better (smoother) when the sensors were returned to their correct location in the exhaust pipes.


Cambos tune can easily dispense with the EML light as it is able to disregard the cat efficiency alert (no more eml light :-))

 

Caldoofy when you say it was over fuelling do you mean your fuel consumption got worse.

 

Caldoofy,

Would your approach to not using bongs or mini cats trigger the check engine light, hence your comment about the tune taking care of the light?

I ask because my city requires emissions testing and I don't want to fail if I install 200 cell cats.

Thanks