Quick question on high flow cat

4.2 V8 32v Naturally Aspirated - 414 bhp
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dogtanion
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Quick question on high flow cat

Post by dogtanion » Sun Jul 17, 2016 10:02 pm

Hi

I am thinking of getting the Magnaflow high flow cat/downpipe to replace the stock cats, to go with the ECS h pipe which I got a couple of years back.

I have read to avoid an engine warning light I would need to weld an o2 sensor fitting to the rear of the cat and plug the provided hole just in front of the cat so that the o2 sensors are either side of the cat.

Anyone know/tried this or know different ?

Thanks

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RichieRS
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Location: Cheshire

Re: Quick question on high flow cat

Post by RichieRS » Mon Jul 18, 2016 12:30 am

Basically, you have 2 sensors per bank. 1 sensor before the cats and 1 sensor between the precat and main cat.

If you are currently running standard downpipes and haven't got a stage 2 map then you will need to put spacers on the second lambda which sits just in front of the main cat once you have fitted the new high flow cats. This is not guaranteed to work though and ideally a stage 2 from the likes of MRC would be preferred as this removes the issue without the need of spacers
Last edited by RichieRS on Mon Jul 18, 2016 8:44 am, edited 1 time in total.

Seattle-squash
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Re: Quick question on high flow cat

Post by Seattle-squash » Mon Jul 18, 2016 12:49 am

Track down/pm the member dufferdude, nice guy and I think he runs the exact setup in his RS4 with a sick sounding exhaust! My next upgrade.

dogtanion
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Re: Quick question on high flow cat

Post by dogtanion » Wed Jul 20, 2016 12:00 am

Thanks for the replies. Sounds like I need spacers in the first instance.

rs4pat
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Re: Quick question on high flow cat

Post by rs4pat » Wed Jul 20, 2016 10:37 am

If you get a stage 2 map that stops it think

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