Hello everyone! First time poster, long time reader of this forum. I know there are lots of bright people here that know way more than I do, and hopefully may be able to help me with an issue.

I picked up this car in May, drove it stock for about two months and about a month ago have gotten catless downpipes, intake, and a tune installed on my 2016 C63S. (Tune was from a reputable tuner who I won’t disclose YET) When I had gotten the tune after I had the parts installed I thought it would be a world of a difference however I think the loudness of the car tricked me into thinking it was faster than it really was. I ended up buying a dragy and testing the car 60-130 mph since this usually a good indicator of how quick a car is without going on a dyno. The car averages about 10.0 flat. Quicker on cool days, slower on hot days. After some research, you can see that 10.0 is stock C63S times. I run some live data logs with the tuner and we find the car is pulling a substantial amount of timing at WOT in multiple cylinders, hence causing it to be slower. Tuner tells me to replace coil packs, and spark plugs. I do as he asked as I’m unsure what was done maintenance wise prior to my ownership anyways. After doing this the car isn’t “fixed” or faster. The tuner is insisting something is wrong with the car, however I have a very close friends who used to work at Mercedes as a tech and also has an independent Mercedes shop.

After scanning the car with Xentry and every tool he has, the car is running perfectly fine and the car is not popping any codes whatsoever. I’m currently trying to data log the car with HPTuners , which is proving very difficult for some reason, but has anyone else ran into an issue like this before?

 

Man sorry to hear ...

What type of tune was it that you got ?? (everyone has there own definitions and its like now there is a Stage 200 and some stupid crap)
(or was the tune simply to remove the CEL for the DP's) ?

Performance gain from just the DP's isnt much if anything without some of the other.

 

Our cars can be sensitive especially with our questionable build quality and 3 things will cause power issues on our prefacelift cars, especially during tuning.

Coils (you fixed)
Spark plugs (you fixed)
Rear exhaust flap actuators not working properly/getting stuck and causing car to limit power

You need to get your car on the dyno and properly looked at. Power curve must be seen/inspected.

Yours has the performance exhaust right?

 

Are you using oe tuning?

 

Hey! And yes it was supposed to be a stage 2 tune, so a little more on the aggressive side and should definitely be noticeable from stock!

 

Yes I have read countless times online that these cars are finnicky. Funny enough you’re correct, the car did have the code for the exhaust flaps, however we coded them out, and the flaps were fixed open for the time being. I wanna say that it’s another one of these weird sensitive issues with our cars but i’m running out of ideas.

I’m in the process of trying to data log but it’s harder than I thought without some help.

 

yea man something up, a stage 2 tune from stock would knock your nickers off ! you would know instantly and feel it.

 

No I am not

 

Thats what I keep reading but the car is still slow 😭 Make’s me regret coming back to amg and almost like I would like to get rid of the car before dumping thousands of dollars more to find a solution.

 

well i wouldnt go that far…

IMO its the tune …

when you remove all the tune, what error codes you get ??

is yours a sedan or coupe ?

 

I second the recommendation that dyno time is needed. Having runs with and without the tune will give you a good idea if that's what's causing the issue or not.

 

Yes I agree. And no error codes at all, the car seems to be running fine with no issues (except for CEL from being catless). It is a sedan btw.

 

Do you think dyno time would be more effective than trying to data log?

 

IMO, yes. A stage 2 tune should yield a noticeable amount of gains in HP and TQ and seeing what the powerband looks like should shed some more light on the situation. If you're not seeing the gains, I would think that the tune is at fault and should be re-mapped/re-installed again to see if it works.

 

Totally in accordance with the other's suggestions: probably an issue with the tune, so dyno it and see what's up.

For info sake, my tuner (EC) did a pre- and post- dyno of my car. Stock was 470whp and 506wtq, Stage 1 tune brought it to 538whp and 593wtq.

 

Will do, talking to the tuner as to the next steps. I really dont want to have him modify the tune as it has worked flawlessly and been fast for hundreds of other cars out there. I guess we shall see, and thank you for the info.

 

hahahahaaahaha

 

understand what your saying, but every car is different... I have a '16 C63s Sedan as well, and the first tune load on mine had a few minor issues, and even MB had to do a full reset of software on my dash etc, it went nuts (luckily it was warrantied)
I sent the info back to RennTech and in 24 hours I got the update on the HHT, loaded it, and haven't looked back since.

Do not assume "that since it work on others, it works on mine" as many have learned, that is not always the case. Doesnt mean something is wrong with yours, it just is not the same all around.
With respect to the "default tune" files, if your tuner, is a Tuner - then he can go in manually and see whats up... If he is just a "reseller - installer" then he wont have a clue, as he is just loading files that anyone with internet access can download and load up.

But for a "true Stage 2" you should have driven out of the lot, and been crapping your pants from a Stock to Stage 2 (period)
Hell for that matter, did the tuner not drive or check everything ??

Just IMO....

 

I had the same issue with my Eurocharged tune. Never found a fix ended up selling the car after it was down for 9 months for a turbo upgrade package that they could never get running right. Their stage 2 tune ran the same times as stock and a pure 900 package ran the same as what stage 2 should have been.

All in all 20k down the drain with not so much as an apology or any offer of compensation from the location or jerry even after reaching out to him personally. If it’s Eurocharged just try a different company don’t waste your time or money with them. Especially if you are working with the Orlando location.

 

Yeah, not a fan of Eurocharged tunes. There are much better offerings out there.

 

Well the OP doesnt want to name the tuner (for what ever reason/s) so we have no idea....
The details of the STAGE 2, are limited , and like I have said before, so many people say a Stage 2 is this and that and this.. blah blah blah... When I did Stage 2, it was fuel lines to handle the extra pressure, boosted PSI ( opt turbo upgrade ) etc etc.. so who knows whats what, as without knowing the Tuner and or Package they claim is a STAGE 2 , its like the other dude who hit a Racoon ...

 

I'm just speaking from my past experience with EC on my 204 from the above poster... It was a nightmare and made my car undrivable in certain settings so I'm not a fan. I would also like to know the name of the tuner in this circumstance as it's for the betterment of the entire community to have visibility on all experiences and issues.

 

I have always had very good luck with EC. Most of the guys in my car club have EC or Labworx and never many issues.

 

You guys then are the lucky few... lol

 

same here, never had a problem and have used their tunes on every AMG car I've owned....