Dally

Like I said, SEEMINGLY, after the res and 2nd cat cut and replace with a stainless X pipe and tubes its loud...ya, that's the good part.


and it never did the bad part before this cut and replace...


The BAD part is, hot or cold, driven hard or soft...completely at random for no reason I can think of it intermittently doesn't have half of the snappy rev it can and should at all times, when being revved in idle.


Other times, it does. It snappily revs and sounds like a beast on fire.




But, it completely unpredictably doesn't at times...Its almost as if it just simply doesn't respond for a second or two to punching the gas pedal...or it simply hesitates and then climbs the revs really slowly and weakly.


The needle jumps a millimeter or so up and down and you can feel the car shake a little from time to time as well...


What I can do however is rev the snot out of it, till it seemingly realizes its a C63 and then gets back to its normal snappy revs like we all love.




What in the ...?


No other mods, no chips, no filters, nothing...


30k kms on it...oil changed 4k ago...NO CEL, no other issues.


Thoughts?

INS1GNIA

Could it be a leak? You could always take it back to the shop and ask them to run through it to makes sure everything is sealed up.

Also reset your ECU.
The procedure to reset the ECU is as follows:

1. Turn the ignition key to the "on" position which is just before you crank the engine to start.
2. Press the accelerator to the floor and hold for 5 seconds.
3. Then turn the key to the off position but do not remove the key, then release the accelerator.
4. Wait at least 2 minutes, the ECU is then reset.
5. ECU is now reset and you are ready to get new rear tires.

The ECU reset procedure only erases the adaptive transmission and throttle settings. It does not erase any of the fuel, timing or other programming.

Read more: Easiest way to reset my ECU

Dally

I figured the same thing. I was thinking it seems like the car is having a hard time matching the fuel to the air if the pipes are hot and swelled and sealed or cold and sealed or vice versa... but then again, its very random and hot or cold so I'm stumped.


I think ill try the ecu reset...problem is I have keyless push start button...

Shadykit

You can always pull the start button out to use your key. It pops right out

Dally

Geesus...learn something new everyday


Cheers fellas, ill let ya know.

Glbaraban

Hey, I got the same issue. let me know if that helps

Dally

oh...interesting...is that after you had the 2nd cat and res cut and replaced with x pipe as well?


I'm going to reset it right now then rip it...brb

Glbaraban

I bought a car with x-pipe. I know it was welded not good so I may have a leak somewhere.
Going to delete resonator and to check for the leaks again.

After the tune - nothing has changed.

Dally

well that was interesting...


I reset it twice to be sure.


Revved it, change...still soft baby lamb revs...


Then ripped it tim hortons and its definitely faster...snappier, arrogant and reminded me of why I bought this car in the first place...it put that smile back on my face.


Then while in the drive thru line for coffee, considering a chocolate glazed tim bit to match the one now fresh in my shorts, I revved it again, hoping for the anger...


and got baby lamb again...


pissed I didn't get the tim bit but got the coffee and ripped it away...again, reminding me of the power of the C63's....


thinkin to myself maybe its just me..maybe its just my ears...maybe I'm not as intuitive to my cars sounds and blips and gurgles as I'd like to think I am...I parked it.


Then revved it again and it snapped at me like I remembered...exactly like... vindicating that I DO in fact know my car/cars and this is an issue...


but still left me at square one...post one...same issue...sigh


what in the hell is going on here gentlemen....

Glbaraban

do you feel a power loss, or just noise difference?

Dally

When in park only...and revving it, power loss and noise difference...big time noise difference, feels less powerful.


Driving it, especially after the reset just now, damn...no loss in power, if not more.

Glbaraban

I thought I was the only one... Ok, we need to check weldings.

Maybe someone else on the forum will help.

Dally

and here I thought I WAS the only one...


LOL


We do...and then shaddapp all the people who've said...I CAN'T be a leak...a leak wouldn't do that...


we'll see wont we...


when you goin?

INS1GNIA

What mode are you using/driving in, C/S/S+/M? If you are revving it in C mode, I can understand the difference in tone. Also the more aggressive and consistently you drive in S,S+,M the more the car adapts to that type of driving. Also lower your rear seats, you'll be able to hear the exhaust note better .

tpliquid

oh i didnt know c would make it quietier

Dally

Forgot to mention that actually, yes tested in all modes a few times and its the same across the board for that 'testing session'


Its been sitting for a couple hours now...I bet I go outside and fire it up and its nasty...meaning lovely.


Morning starts are always eye opening ear cleaning. But by the time I get to work, c, s, s plus or M ...shes a baby lamb during revving.


I got a MB scanner going on it tomorrow without cel's but apparently the logfiles will show something if it doesn't throw a cel.


thanks gents.

Dally

my seats are sunk flat...im 6' 4 lol and I drive with the window down in minus 20 to hear it lol


ill try ripping it in S plus all the way to the mall then test it when I get there...update all later

INS1GNIA

Haha, yea I'm sure the fit is a bit tight.

A good video for reference on sound:
<iframe width="560" height="315" src="https://www.youtube.com/embed/iK2DILwmcuQ" frameborder="0" allowfullscreen></iframe>

ArmoE55

Is every C63 able to lower the rear seats? I'm very new to the C63 but I couldn't find how to lower my rear seats, I tried every trick and looked everywhere.

I don't think my car is able to lower the rear seats ... ? Thank you.

Eric ATP

Do u have an owners manual? You can buy one on eBay pretty cheap.
Look in ur trunk. You will see the rear seat release there.

CPD SLK

A leak or maybe if the new piping is hitting the body underneath maybe it is pulling timing because of knock? I have the resonator delete but not the 2ndary pipes...that's next!

Blake_von_Texas

I have experienced the described "sluggish" rev in park only once and it was the day that I deleted the secondary cats. I personally believe it has the do with the difference in exhaust pressure? I suppose its possible that the ECU isn't compensating properly when the motor has no load on it.

ArmoE55

Yes, I have an owner's manual and read it thoroughly. The OM has two handles pictured in the trunk to release the backseats to fold them forward and expose the trunk. However, my car does not have the release handles in the trunk - that's why I asked if ALL C63s can fold the seats down - or maybe there is another way to do it? I looked all through the trunk and also went inside the car - nothing to fold the seats down.

Any thoughts? Thank you.


OP - sorry for the thread hijack!

Dally

Watch "2nd cats cut no res replaced with ss X pipe" on YouTube
And then this...

She was healthy above... Then slowly.. Surely it's worsened

Like here in C mode

Watch "Res cat cut but... Somethings up" on YouTube
Watch "Res cat cut xpipe" on YouTube

Glbaraban

any updates?