elealschuman

I just noticed today on my 2016 c450 with the performance exhaust that always has made the best pop and crackles is no longer doing it. Maybe this will change as so far it’s only been a day. The other thing is that i grille swapped today from the stock diamond grille to the gtr panamericana grille. Maybe it has something to do with airflow since the new grille allows a lot more air to flow through it? I don’t really know just a thought. Anybody has this issue or know what could be up?

DirtyDD

I thought the performance exhaust option was not offered on the C450? It was first offered on the C43. Do you have the performance exhaust button on your center console?

Changing your grill will not effect exhaust sound. Did the dealer do a software update?

elealschuman

It is offered but there is not button the center console. The way you turn it on is by putting the car into sport+ mode. I’m 100% confident it is an option though because although i bought it used, the description said it was an option that was on it and purely because of the amazing and loud sounds it usually makes rhat are identical to the c43’s with the button. It’s only been a day and i haven’t taken it to the dealer yet, but do you think that would be best option. I know the exhaust is purely ECU controlled which is why the grille theory doesn’t make sense, it’s just odd that the day i switch it the exhaust starts having issues.

C43HeartBoost

The first thing that comes to mind is that your car is in a soft limp mode from either a bad batch of gas or your battery being low. Neither of these will necessarily cause a CEL, but will cause your car to retard timing and adjust fuel. If you had the doors or other car electronics on when you did your grill swap, it may have drained the battery to the point of soft limp mode. Do you have Dragy? If so, do a few pulls to compare prior performance to current.

elealschuman

I do not have a dragy yet unfortunately, although I am looking to get one soon. I had the car on for short amounts of time while turning the wheels to get into the wheel wells or to test if the electrical wiring that was unplugged and then replugged still worked, but the car wasn't on the whole time. If that's the case however, do you know how I could get the battery out of the soft limp mode? I read stuff about the gas being a factor with this but I just refueled at the same station I always go to with 91 octane that always produces the pops and crackles, so I don't think it has to do with the gas.

C43HeartBoost

An OBD-2 code reader will tell you if you have soft limp mode codes. Otherwise, a volt meter will tell you the battery’s charge. I know some auto parts stores will test either for free. Also, I would not discount a bad tank of gas as the potential culprit. Many states adjust the ethanol content of gas by season of the year. I run an e85 blend and can tell you I get more pops with the e85 blend than without (catless downpipes).

DirtyDD

Nah. Search the web. There is no PE option on a C450. They all come with the same exhaust.

Get under your car and get a picture of the exhaust where it goes into the diffuser. There would be valves there that are activated by the button in the console. There wont be any.

elealschuman

I'm new to cars in general and this car specifically so you're probably right, but regardless of if it's the performance exhaust or not, it used to make all the loud pops and cracks and now it's not so all I need to figure out is how to get those back.

elealschuman

Okay thank you for that information. I'll wait till this tank is empty and I refuel to see if they come back, but if they don't then I think I'll take it to a store where they can get me those readings. Thanks for helping figure this out w me, this has been very helpful and informative.

gpouliniii

Its not the gas at all. My C450 has not made the pops in months and I’ve tried the E85 mix, the ECU/TCU reset and still nothing. It quit doing it before I added the JB4 and even after adding that, they didn’t come back. However, I’m pretty sure they quit after I added an MST intake and the BMS blow off valve spacers. I also have a P0500 code which is the O2 sensor heater of component (which I haven’t gotten around to replacing yet), so it’s possible that the blow off valve spacer and or dirty air filter could be the culprit and possibly the 02 sensor, but if you guys don’t have CEL’s on, I’m wondering if it could be the air filters, I seriously doubt it, but it’s possible. I run 93 in mine 95% of the time too. I usually only put the E85 mix in when I’m near a station that carrys it, but it’s def not your gas choice. I did the reset and then filled up with the E85 mix and still nothing.

elealschuman

Damn. All my internals are completely stock though and it's not like they just faded out, it just has completely stopped and I have no clue why. I think I'm just taking it into the shop after I re-fill with new gas and do the ECU reset by disconnecting the battery today if that doesn't work out. I've been doing lots of reading and have found countless people with similar issues to you and I so I'm wondering if it could literally just be a mileage thing since the cars are getting a bit older. How many miles are on your car or about how many were when the pops went away?

elealschuman

UPDATE: I recently reset the ECU and TCU and the burbbles have definitely returned when letting off from anywhere around 3.5k rpms and under, even in Eco mode (this makes me think something is just wrong with my exaust in general). However, although I'm getting the nice burbbles when letting off from lower rpms, when I left off from anywhere above 4.5k hoping to get the aggressive and loud pops and real bangs, I get absolutely nothing, not even a burble. Anybody have any idea of what's going on lol?

W205C43PFL

In that case, you just need to drive the car more often in Sport+ for the car to learn your driving behaviour again since you reset everything. For example, when I was breaking-in the vehicle and kept the RPM low and stuff, vehicle doesn't burble and pop as much as the vehicle thinks I like to drive calmly, a few days after driving in Sport+ post break-in the vehicle gives such nice pops and bangs.

elealschuman

Alright i’ll make sure to do that. I’ll give another update after about a week of driving in sport +. I’m also gonna be refueling soon so maybe that will have an effect too.

W205C43PFL

Sounds good (pun intended) and good luck, hopefully they return soon, enjoy your vehicle!

W205C43PFL

Speaking of refueling, what ethanol content does your local gas station have? That alone should not really affect the pops and crackles but just want to make sure.

elealschuman

Honestly, I don't know and couldn't figure out the ethanol content I just know it's 91 octane as that's the highest available around me. However, I'm happy to say that the pops and bangs have returned (even coming down from redline)! I plugged in an obd2 and deleted the only code that popped up, but it looked like it had something to my outter temp gauge (like weather temp), but I deleted it nonetheless and first time I put it back into sport plus everything was back to normal. Still don't really know what the exact issue was, but happy everything is back to normal!

W205C43PFL

Thanks for your update, glad to hear that the pops and bangs came back after clearing the stored code.

alemC43

So, after resetting ECU and deleting codes pops and cracks came back? Have to try that. I’m so frustrated since my last service. After a dealer’s software update my car completely changed, it’s like driving a regular car. Have you changed gas type? Thanks.

W205C43PFL

The update might had performed a reset of your adaptations, driving it in sport+ more will likely bring it back if your vehicle doesn't have stored codes.

elealschuman

Okay so I actually did the grille installation taking off the front bumper again on the same car, and this time I had the same problem after the grille swap of no pops and bangs. I figured out quite easily this time what my specific problem was however. When you remove the front bumper and unplug the main wiring harness your o2 sensor (called the ambient air temperature sensor code on the obd2) is unplugged and reset. The second I noticed they were gone I plugged in the obd2, deleted the ambient air temperature sensor code, and immediately they returned. I have not changed gas type, still on 91 octane from the station which is the highest available near me. A dealer update may be a bit more permanent than my situation, but I think it's 100% worth plugging in an obd2 and if you see any code about an o2 sensor or ambient temp sensor, delete it and you should have your pops and bangs back. Hope that helps.

alemC43

Hello, elealschuman. What OBD reader did you use to delete MB codes? I've tried a couple already on my C43 and does not allow me to delete anything. I'm having the same issue with pops and cracks gone after a brilliant MB dealer' software update. Thank you.

elealschuman

Attached is the link to the exact one I have. $35 bucks on amazon and you should be good to go.

alemC43

Awesome! will try it. Thank you, elealschuman!

Mvxc

have you had anymore issues? I had the exact issue and I might be able to help