MHD Tune - Engine Malfunction Reduced Power

[jinuwin]

Just flashed MHD Stage 1+ on N55 yesterday. When I was driving home on the highway, I got the Engine Malfunction Reduced Power light on. As I drove home, car shakes rather violently like my tire had blown.

When I coasted home and parked, I ran the codes. I also noticed the smell of gas from outside the car.

2 codes that popped up (P0306):

1. Faultcode: (0x2EF4) Misfiring, Cylinder 6: injection cut
2. Faultcode: (0x2EF6) Misfiring, cylinder 6: exhaust gas harmful to start operation

Anybody know what the possible issue is and the fix? Issues like this kind of discourage me from flashing my car again...

[m5james]

I've got an MHD tune on the GF's 535xiT, best $150 I've ever spent on her car and kicking myself that we didn't do it sooner. Flash back to stock, see if it remains and then flash back to stage 1/1+ or whatever you went with. You've gotta realize flashing and increasing power is going to make the power more pronounced...as well as what needs attention.

[jinuwin]

Originally Posted by m5james

I've got an MHD tune on the GF's 535xiT, best $150 I've ever spent on her car and kicking myself that we didn't do it sooner. Flash back to stock, see if it remains and then flash back to stage 1/1+ or whatever you went with. You've gotta realize flashing and increasing power is going to make the power more pronounced...as well as what needs attention.

I just flashed back to stock and the light still comes on. Car shakes violently and gas fumes still present . I just can't believe this happens a day after flashing... I'm thinking either spark plugs, coils, injector or fuel pump have gone, need more input.

[m5james]

Sounds like the tune just sped up an existing issue. Body wise you're fine coming here, but engine wise you're likely better off going to N54Tech.com.

[jinuwin]

Originally Posted by m5james

Sounds like the tune just sped up an existing issue. Body wise you're fine coming here, but engine wise you're likely better off going to N54Tech.com.

Started her up today with the stock flash and all seems well . Rough idle/vibration gone and no errors. Yesterday, Carly managed to pull up 40 faults with the tune lol.

[yco]

you can start checking from spark plugs.. and since you changed the engine map try to stick with higher octane fuel..

[jinuwin]

Originally Posted by yco

you can start checking from spark plugs.. and since you changed the engine map try to stick with higher octane fuel..

Been chasing misfires past 2 weeks. Changed all spark plugs and faulty coils. No more codes. However, now the car jerks/rumbles in idle or at stop. Goes away once I put throttle. Anyone know what's the issue?

[Bmf007]

So I just flashed my 2013 x6 35i and hell broke loose. Didnt k ow I had so many lights come on. Well I guess I was supposed to unlock the mde first well didnt know that.

[jinuwin]

Originally Posted by Bmf007

So I just flashed my 2013 x6 35i and hell broke loose. Didnt k ow I had so many lights come on. Well I guess I was supposed to unlock the mde first well didnt know that.

Lights came on during the flash for me. After I started the car they all cleared. Did you check on realoem if your DME is codeable? Try flashing back to stock if anything.

[yco]

Originally Posted by jinuwin

Been chasing misfires past 2 weeks. Changed all spark plugs and faulty coils. No more codes. However, now the car jerks/rumbles in idle or at stop. Goes away once I put throttle. Anyone know what's the issue?

can be engine mounts which i believe it can be fuel filter, fuel piping or the pump.. or the biggest one timing belt.. but in the end since engine map is changed maybe an update for it can help though as fast and free solution..

[m5james]

I read from a tuner that they ECU needs to be cracked before flashing. All this talk of flashing issues...have you written MHD directly yet? They're very responsive on Facebook Messenger.

[jinuwin]

Update: found out that those idle pulses/jerking of the engine was indeed misfires... got the codes to popup under WOT and swapped coil and the error didn't follow. Was worried I had to replace injectors but nope. When I installed brand new Bosch double platinum plugs I forgot to gap them. I guess the spark ground can get loose from handling. Always check gaps when installing new plugs!

[peter2772000]

Glad you got it figured out!!!

[Bmf007]

Well hope to get my ecu back with my DME unlocked tom and them hope to flash it with mhd stage 2 +. Well wish me luck hope this works out.

[Bmf007]

Well just flashed my x6 35i with mhd stage 2+ mad and all I can say is wow. Took it for a quick drive and man it's like a new car. Cant wait to pit some miles on it tom. Glad I did it so let's see what happens after some driving. 😃