[GiorgioIr]

Hey guys, I was driving normally until I was driving up a hill and I felt like flooring the car. So I turned the DSC completely off, (was driving in first gear) and floored it. When the RPM needle hit 7000 Rpm (and everything was top notch), the car did shift into second gear like usual (auto), but this time accompanied with 3 LOUD consecutive bangs that came from the exhaust "BABABA" like that; it sounded the same as 2step. So i immediatly let my foot of the gas pedal and the car started vibrating like crazy as if it was misfiring. so I parked, turned the car off for 10 seconds, started it again and everything is back to normal.
When I got to work, I parked it, let it rest for 1 hour, then checked underneath for oil or something and found nothing.

things you should know:
I have JB+, ERCP, Dci's, muffler delete.

I have also replaced the HPFP (newest serial) 4-5 months ago.

Any thoughts about this? I'm def. worried!

[HighPSI]

No codes? Sounds like you misfired

[GiorgioIr]

Originally Posted by HighPSI

No codes? Sounds like you misfired

Ill go tomorow morning to the local mechanic to see if any codes got thrown since I dont have a scanner yet. Btw ECL didn't come on.

[GiorgioIr]

Should I drive the car back home or I leave it here?

[HighPSI]

Drive it home

[MrRetep]

Are you sure it shifted? It sounds almost like it was bouncing off the rev limiter. I know the AT shouldnt do this, but if it was a misfire the car wouldve shuddered heavily as well. Please update us when possible.

[Cali FlyBoyZ]

It's definitely probably a misfire lol... no, but seriously try checking the codes it threw. I had the same issue. I have a cobb tune and once I reach about 15psi, I too would hear a bang and a weird note coming from the exhaust. Turning the car off def made it go back to normal, but if I punched it, I would get the same exact problem. I changed the ignition coils and spark plugs and the issue went away. You may only need to change the spark plugs, but Im at 80k and drive like a maniac, so I changed both lol

[marv85]

Originally Posted by GiorgioIr

Should I drive the car back home or I leave it here?

It seems it drives normally. Just don't floor it until your read the codes.

kifak man? b3atle PM w bse3dak to debug

[Javier]

sometimes the car makes sounds like that when you get wheel spin and the traction control cuts power abruptly... but since you had it switched off, i'm not sure...

did you have it fully off (hold for 3 sec) or just DTC (single press) ?

[dicostal]

sounds like you have a bad injector\s
it may be gone for good, but if it comes back, my money is on the injectors as I recently experienced the same

[135Pats]

sounds like a bad misfire, you should have codes stored. If the car starts OK with no limp mode, you should be fine to drive home. Id keep throttle loads modest though. Good news is if it is a misfire, plugs and/ or a few new injectors outta take care of it.

[N54King]

Had the same problem when i was fully stock ... ended up being an ignition coil

[Goofyguy]

Mine will shift but in transission it will bounce a few times off the rev limiter.

[trickcruiser]

Originally Posted by dicostal

sounds like you have a bad injector\s
it may be gone for good, but if it comes back, my money is on the injectors as I recently experienced the same

This was my guess as well. I just had injector 6 go bad and my car was misfiring with bad pops upon deceleration.

[Eric335]

Sounds like a misfire. I got those same NLS/backfire type sounds when i misfired

[Ferruccio]

Sounds like a misfire to me! I've had some pretty scary feeling misfires before. Most of mine went away with replacing the plugs. I still need to replace a coil or two.

[Crazylegs]

I have an AT an have slammed the rev limiter from a 40 in 2nd do to wheel spin. Heard a really large bang then to be launched as the car cought traction no issues though

[Wedge1967]

It's not a misfire, you hit the rev limiter and the throttle body closed. It will cause a loud backfire.

[GiorgioIr]

Originally Posted by MrRetep

Are you sure it shifted? It sounds almost like it was bouncing off the rev limiter. I know the AT shouldnt do this, but if it was a misfire the car wouldve shuddered heavily as well. Please update us when possible.

Yes it shifted to second gear. What I noticed is that whenever I try to push the car now above 4k rpm with full throttle, the car seems to choke, So Its propably its a fuel issue (ether hpfp or injectors) but I'm gonna have my coils tested too. (I had my spark plugs changed 10k miles ago)
Yeah It shifted, the mechanic gave me an appointment scheduled to tomorrow since he had too many customers.. so luckily I'll update you guys tomorrow.

Originally Posted by Cali FlyBoyZ

It's definitely probably a misfire lol... no, but seriously try checking the codes it threw. I had the same issue. I have a cobb tune and once I reach about 15psi, I too would hear a bang and a weird note coming from the exhaust. Turning the car off def made it go back to normal, but if I punched it, I would get the same exact problem. I changed the ignition coils and spark plugs and the issue went away. You may only need to change the spark plugs, but Im at 80k and drive like a maniac, so I changed both lol

Thanks for your input, I changed my spark plugs 10k miles ago, right now I'm suspecting HPFP/injectors since its choking when I give full throttle, but I'll have my coils tested too.

Originally Posted by marv85

It seems it drives normally. Just don't floor it until your read the codes.

kifak man? b3atle PM w bse3dak to debug

That's what I'm doing, Im driving slowly and not exceeding 2.5k rpm. Ana mnih bro but I dont have jb4 or scanner to read the codes, I'm going tomorow to a mechanic w hopefully he'll get it sorted.. Thanks for your help bro appreciate it

Originally Posted by Crazylegs

I have an AT an have slammed the rev limiter from a 40 in 2nd do to wheel spin. Heard a really large bang then to be launched as the car cought traction no issues though

Originally Posted by Wedge1967

It's not a misfire, you hit the rev limiter and the throttle body closed. It will cause a loud backfire.

Originally Posted by Javier

sometimes the car makes sounds like that when you get wheel spin and the traction control cuts power abruptly... but since you had it switched off, i'm not sure...

did you have it fully off (hold for 3 sec) or just DTC (single press) ?

Yeah I know usually I would troggle DTC off (single press) and i press on the gas and like you said, the traction control cuts power abruptly and it would make a bang too.
However, what happened yesterday wasen't normal at all. I had it fully off (3sec) and it made 3 huge bangs very similar to a subaru antilag or 2step (RAPAPAP <- like that) while shifting to second gear after hitting the redline.

Originally Posted by dicostal

sounds like you have a bad injector\s
it may be gone for good, but if it comes back, my money is on the injectors as I recently experienced the same

Yeah I'm currently suspecting ether HPFP or injectors. And no its not gone haha my car chokes wherever I give full throttle above 3k rpm

Originally Posted by 135Pats

sounds like a bad misfire, you should have codes stored. If the car starts OK with no limp mode, you should be fine to drive home. Id keep throttle loads modest though. Good news is if it is a misfire, plugs and/ or a few new injectors outta take care of it.

That's what I did, drove it slowly and kept rpm needle under 2.5k. Going to the mechanic tomorow to read codes/get repaired.. well keep u updated, thanks for your input..

Originally Posted by Ferruccio

Sounds like a misfire to me! I've had some pretty scary feeling misfires before. Most of mine went away with replacing the plugs. I still need to replace a coil or two.

Originally Posted by N54King

Had the same problem when i was fully stock ... ended up being an ignition coil

Yeah Im suspecting primarily HPFP/Injectors and secondarily the coils.. Im going to the mechanic tomorow so we'll see.. Thanks for your input, will let you know if it was my coils or not.

[cn555ic]

29f3. Or 29dc. One of those codes you will have for sure

[MurderedBeemer]

have the same problem, but my half engine light goes on! leaves after a couple of seconds! i used to shit off the car and start it back so it can leave! Now i mostly do highway so i let it run on neutral and the light and shaking leave!

[GiorgioIr]

Originally Posted by MurderedBeemer

have the same problem, but my half engine light goes on! leaves after a couple of seconds! i used to shit off the car and start it back so it can leave! Now i mostly do highway so i let it run on neutral and the light and shaking leave!

it seems that your hpfp needs replacement, because your check engine light (cel) goes on. Besides it already happened to me 3-4 months ago, car chokes (meaning lack of fuel) then starts shaking and having crazy misfires and engine light goes on, turned out that the hpfp needed replacement.
This time in my case, cel light didn't go on, this is why I'm suspecting injectors/coils etc.