Rony Kingmillo

Hello everyone, I had primary and secondary cat delete with tune. The secondary delete was just simply removing the inside without replacing it with X pipe and primary delete replaced with straight pipe. My question is, do i really need an X pipe?
My friend is inviting me to group buy eissenmann exhaust (behind secondary to the back), is x pipe going to give me better upgrade cos I feel I am losing the low end?

Thanks

MaroonC63

X pipe and straight pipes are 5 hp difference at most, i had both set-ups and they felt the same honestly. Wouldnt waste the cash on it. It will smoothen out the sound though, not my personal taste.

Also, a member here did a dyno between straights,x and h. Difference was 1-2hp between all three setups with x giving 19 hp and straights giving 17 h giving 18 i believe but dont hold me to it.

anthony02tolson

do removing or hollowing out your cats make your check engine light come on?

Mort

Yes unless you tune it.

JCAMG63

how do I hollow out my sec cat and leave the stock look for the dealer?

SoFlaC63

You COULD hollow them out. But i do want to remind some people that inside those cats are precious metals. Those cats each are worth atleast $100 each for scrap. BUT i live in Florida where there are no emissions so i don't ever have to worry about it. Just before you destroy those cats, you could sell them or keep them for backup encase you go back to stock to trade in. I mean, exhaust for our cars is pretty dam expensive as it is why not take it off and sell it before you sell the car?

Char_AMG

I have a 2013 c63 sedan (no p31) and I want to do either a resonator delete or 2ndary cat delete.

Which one will not throw codes or errors?

Which one provides more power?

Finally which one is more reliable in terms of long term use. I have a 3 year lease. Some what worried if dealer finds out..

Rib Feast

I have a 2011 facelift C63 and did a 2nd cat delete and x-pipe. It got a little louder, no engine lights.

Used to have a RS4 with Milltek exhaust so still was wanting more. Went back, removed resonator and did a straight pipe. Much better - more backfiring and popping, but still only slightly louder than stock at low rpm.

I had a tune done immediately after the 2nd cat, no engine lights. Didn't do anything after removing the resonators and no engine lights came on.

Definitely recommend the 2nd cat, x-pipe, resonator delete with straightpipe option. It's the perfect combination of slightly more rumble at low rpm, to feral when mashing the loud pedal. Driving in high gears and flooring it is great now too - very nice liquidy v8 sound under load.

Mort

You should not get a code from removing secondary cats as the O2 sensors are before these cats. You will get a code from removing primary cats and will need a tune to eliminate it.

Char_AMG

Thank you for the replies. I am not worried about my primary since I will not touch it. I think I will do a 2ndary car delete over the resonator delete for a reason for some more power gains. I would like to Dyno my car with charcoal delete, new filters, secondary delete in the future.