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Does the car need a remap if the secondary cats are removed
If removed for noise not power

Cheers Adam

In short, I don't know.

I would expect the AFR's to be affected by a sec cat delete, so my inclination is to say yes, a remap advisable.

That said, the ECU's may be able to adjust (learn) sufficiently, so it could be ok.

Think we need an expert opinion here !

You might get a dash warning light due to the lambda's 'reading out of spec'. Again, can't remember if that is an issue for the primary (DP) or secondary cat delete (think it is the sec cat also).

Worst case scenario, do a sec cat delete and find out !! Dash light on, map it out. If you have a Vagcom, you could log to see if the tuning has been thrown out enough to warrant a remap.

Sec cat delete don't bring up faults as they didn't on mine. Sensors are before if I remember right.

Cheers guys

Great set of LED's too Trups

Pretty sure as long as the sensors are kept the ecu will adjust

I took mine in to have the secondary cats and the silencer removed but the garage could not get the sensors off so the job had to be aborted but the sensors are in the cats so these I presume would need to be relocated

I'd be interested to find out the noise difference as this is what I wanted it for.

Interestingly they did an s6 recently who wanted more noise and to get the best sound they took the back boxes off and just piped up straight to end pipes? Seen the car around but not heard it but according to them it was louder but not in your face and was still fairly quiet in the car but it made the car pop and bang on let off which they said sounded amazing?

Sorry if it's a bit OT but can you delete the primary or secondary cats and still pass an MOT or can you get bypass pipes? How much noise will it add as I'd like more power but without more noise and MRC said my exhaust was now my sticking point.

To pass an mot the car will still need cats in place but you don't need two set of cats.

The only other alternative is get a replacement pipe that you can bolt in as and when you do an mot which is what I used to do with my r33 or find a friendly mot centre