I've got an 06 Ram with 5.7 mds. I installed a mopar cai but now I hear a chocking or backpressure type sound when I'm coasting between 1500-2000 rpm. So then I had a magnaflow dual exhaust installed thinking that would allow the air to flow through but it's still doing it. Is this normal? Is it the change in compression when the mds kicks in that I'm hearing? I hope someone knows because this is getting frustrating. [:@][:@][&:]

 

what is a chocking sound

 

It's an abrupt backfiring noise coming from the engine compartment.

 

somewhat like a blow off valve on a turbocharged car? bc if thats it, mine does the same when i down shift sometimes

 

Mine does the exact same thing. I believe they all do, but with the gigantic, and specially engineered, stock intake system it is unhearable. Appears to only occur when MDS kicks in.

 

That's sounds right because I never heard anything until I put in the CAI. And on top of that it seems as if it's when it's going from 4 to 8 cylinders. It's almost as if there's a change in compression and that air is coming up and blowing open my throttle intake port. I'm glad i'm hearing others with the same senarios. Thanks a bunch guys, I really appreciate it.

 

i just have the 4.7 but i have flowmasters and a CAI but every now and then when it down shifts, it has a blow off valve type sound

 

Sorry for the newbie question but im looking into getting a CAI too and just wanted to know if all 06 and up HEMI's have MDS or how do you know if your HEMI has MDSi have an 06' TRX4 Hemi does mine have MDS

 

My buddy bought the same truck you have and he has the MDS on his. I'm not sure if they all have it or if u can buy it without. I would think your truck manual would tell you if it the MDS.

 

Some over at Dodgetalk have complained about noise from theirEGRafter installing a CAI. Their description sounds similar to what you are describing.
Could this be the sound your hearing?

Tom