I recently installed a Magnaflow catback exhaust on my car and while it sounds great from the outside, it's headache inducing with the booming noise it creates in the cabin during throttle application from 1.5k-4k rpm. Can anyone else with a Magnaflow exhaust chime in with their experience? Is there a cheap fix to bring the inside noise levels down? I had a Magnaflow exhaust on my Subaru and it wasn't nearly this bad inside.

Edit: Does anyone know whether this resonator will help, and if so, will it fit to the midpipe without hitting the underside body? http://vibrantperformance.com/catalo...roducts_id=292

 

So, here is the resonator that I proposed to use on my Ralliart:

http://www.flowmastermufflers.com/index.php?page=152

The company used to be called "Hushpower", but they were recently purchased by Flowmaster. The particular resonators are in the DBX series (including the HP2).

HP2 resonator on an Eclipse with a similar exhaust setup:

http://www.youtube.com/watch?v=YrGCBrrgX0g

 

It sounds almost like an MKIV Supra with that setup. Me likey.

 

Can an exhaust leak at the inlet junction or at one of the clamp points cause the booming effect? I really don't want to throw money on top of the exhaust if I can't be 100% sure it'll fix it.

 

Yes.

 

Check your clamps and tighten them again. I've had a few leaks and the sound was unbearable... I thought that's what it's suppose to sound like after the break in but nope.

It's perfect now after 4 tightens in 6 different months lol...

 

I added a test pipe in addition to my catback and it got much, much louder.

I had assumed that was the way it was suppose to sound.

I eneded up going under the car and turning the ignition on and you could feel the leak comining from the test pipe / midpipe flange.

Retigten by hand and added rtv high temp gasket sealer and the car sounds great again!

 

Thanks for the input guys. I'll take the car back to the place that installed the exhaust and have them take a look at it. Hopefully it just needs a new gasket/exhaust paste with some tightening and I'll be good to go.

 

Well my car just threw a P061A code. I was accelerating on the highway and then power just cut out. Restarted it first time, and the idle was going up/down. Shut it down for a minute or so and then it was fine. Anyone know what this code means for a Mitsubishi?

This is what I found online:

P061A-ETC LEVEL 2 TORQUE PERFORMANCE
For a complete wiring diagram Refer to Section 8W.

Theory of Operation


This algorithm monitors the control system to ensure that the fueling output is consistent based on the operating conditions. The ECM will light the ETC lamp immediately after the diagnostic runs and fails. During this time the customer may experience an engine derate or engine running rough. The ECM will turn off the ETC lamp once the diagnostic passes in one drive cycle.

When Monitored:
Engine running.

Set Condition:
Varies with operation. Verifies the control system fueling output is consistent based on the operating conditions.

 

You probably over boosted and hit the torque limiter. Need to tune.

 

I'm running Cobb's stage 1 93 map which they claim is fine with a catback exhaust. No other mods on my car. The power cut happened in 5th or 6th gear with 50%+ throttle. I'm guessing the stock map would have the same issue if I flashed back?

The exhaust sounded fine on my way to work today too, which is odd. It was a little "boomy" after 20 minutes or so on city streets so I don't know if the exhaust is breaking in or I'm just getting used to the sound. It sounds fine outside and I can't really hear any gases escaping at either of the clamp points.

 

I've never seen the P061A, and Google wasn't much help but codes in that area (P06x) are all related to the exhaust, namely the O2 sensors.

This is looking more and more like an exhaust leak.

 

Went to another shop and they said the exhaust has no leak at any of the three points. Looked at it up on the lift and there's nothing to indicate it; no abnormal sound or actual exhaust gas fluttering when they closed the tips.

 

I have a magnaflow and it doesn't boom. It's a little louder on decel but it's not that loud. I even run a test pipe, although it's a mini muffler test pipe.

It's probably half the loudness as my Evo. Which has a Vishnu 3" signature series exhaust (magnaflow muffler, straight 3" no resonators)

 

you can try putting some dyno matting in.