CEL from high flow cats

[FIFTY]

I am fed up of staring at the CEL light or resetting it all of the time especially after 2 weeks on the road non-stop with it beaming at me so I have decided to do something about it

I have a primary cat delete and the secondaries are only 100 cell each - apparently if the fabricator used 200 cell cats instead the CEL would not turn on at all. The error I get is to do with cat efficiency (cannot remember the exact code but I can check)... AV has confirmed that it is definitely that the cats are not cleaning the emissions as well as the ECU would like.

I know what the solution is so i have decided to get on with it, ordered up a couple of lambda spacers for less than £6 for the pair, these will screw into the second lot of sensors post cat and restrict the airflow of exhaust gasses to the lambda hopefully tricking the ECU into thinking the flow has been restricted by the cats. https://www.ebay.co.uk/itm/Stainless-Lambda-O2-Oxygen-Sensor-Extender-Spacer-for-Decat-Hydrogen-M18x1-5-UK/123343642370?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649

If this does not work then the next solution is a little more pricey but should definitely work, spacers with a mini cat welded into it - the fabspeed ones look pretty good quality: https://www.fabspeed.com/universal-o2-spacer-with-catalytic-converter-single/

Will update how I get on but hopefully it shows a simple solution to what puts a lot of people off up-rating the cat section.

 

[conaero]

Have you checked the secondary air pipe that runs round the front of the engine is not rotted through and leaking resulting of loss of air pressure into the cats on start up?

 

[FIFTY]

Secondary air pipe is A-OK, I inspected it when the bumper was off last month

It started doing it straight after the new cat section was fabricated and fitted I have been too lazy to fix it myself

I did take it back to the place who fab'd it and they did not want to know.

 

[redsonnylee]

Secondary air pipe is A-OK, I inspected it when the bumper was off last month

It started doing it straight after the new cat section was fabricated and fitted I have been too lazy to fix it myself

I did take it back to the place who fab'd it and they did not want to know.

That’s shocking they obviously don’t care about their reputation

 

[Gp79]

Would fitting the restrictors make any difference? as the lambda sensor is measuring the O2 content not the flow.
Still it is worth a shot for £6
Or can the ecu be remapped for the 100 cells - will cost more than £6!

 

[FIFTY]

That’s shocking they obviously don’t care about their reputation

Seems a pretty common atitude these days

 

[allandwf]

Would fitting the restrictors make any difference? as the lambda sensor is measuring the O2 content not the flow.
Still it is worth a shot for £6
Or can the ecu be remapped for the 100 cells - will cost more than £6!

I think you trick it by raising it out of the flow?

 

[CatmanV2]

I think you trick it by raising it out of the flow?

That was my understanding as well. Although these do appear to have some flow limitation as well

C

 

[Jonathan]

I have this same issue also. .diagnosed by a specialist..might try those spacers. ..are they easy to fit?

 

[Zep]

I have to say I am sceptical of the spacers, if the exhaust chemistry is wrong, seeing less of it (due to it being further from the flow) will still mean a problem. I can see that the spacer would help for intermittent emissions issues as it would reduce the sensitivity to short term issues.

The mini cats are very likely to work though.

I observe with interest.

 

[Jonathan]

For £6 a go should be worth a try if it's an easy fit..I believe there are 4 sensors...do they all need a spacer fitted?

 

[Zep]

No harm in trying. Fitting can in interesting, threads that have been at a few hundred degrees over and over can be on the tight side (by which I mean really really hard to undo).

Recommend a Lambda removal tool instead of a spanner and a long bar for leverage.

 

[alfatwo]

Why don't you just stick to the manufacture's standard system... lets face it in a couple of years time any messing about with non standard emission stuff will end up with your car being a permanent museum piece!

Dave

 

[Jonathan]

Well a) I bought the car with nonstandard exhaust and cats so retro fitting standard ones will be expensive and b) it sounds AWE SOME

 

[allandwf]

No harm in trying. Fitting can in interesting, threads that have been at a few hundred degrees over and over can be on the tight side (by which I mean really really hard to undo).

Recommend a Lambda removal tool instead of a spanner and a long bar for leverage.

Very wise, an invaluable tool.
I was in the fortunate position of having the cats out, so lambda in the vice, and turn the cat!

 

[allandwf]

It's also advisable to avoid WD40 on O2 sensors, some don't like it.

 

[alfatwo]

Well a) I bought the car with nonstandard exhaust and cats so retro fitting standard ones will be expensive and b) it sounds AWE SOME

You have to be carful though, once logged onto the system as a emission's fail due to inappropriate modifications your done!

Dave

 

[TimR]

That’s shocking they obviously don’t care about their reputation

Why..? If you ask for 100 cell cats...
Outrage is all very well but somewhere along the way, you have to take responsibility for own decisions....!

You have to be carful though, once logged onto the system as a emission's fail due to inappropriate modifications your done!

Dave

This is scaremongering...!
I dont understand why you didnt have them made with 200 cell cats.... I mean, a primary delete AND 100cell 2nd cats...
Dont forget your earplugs....

 

[allandwf]

Out of interest, how many cells is a standard cat?

 

[FIFTY]

P

Why don't you just stick to the manufacture's standard system... lets face it in a couple of years time any messing about with non standard emission stuff will end up with your car being a permanent museum piece!

Dave

Prefacelift 4200 cat section has 4 ceramic cats which expire in a spectacular way when I bought mine they were full of sand from the ceramic breaking up and lucky it did not blow back into the engine. The car should have never had these; it is a design flaw... You can go ahead and spend £3k with maserati on a new cat section that will fail in 30-50kmiles

@TimR I was expecting him to fit 200 cell magnaflow cats but he said he bought these and they will pass the MOT and so on... They were fitted and hindsight is a powerful tool in not making the same mistakes again but it will not undo existing mistakes... I plan to replace the cat section with new larini section when in a few years but would like a short term solution to the cel

@Zep the CEL does not come on immediately it takes a few hours of driving generally motorway cruise after 2-6 hours