OK I know I am not the first to do this, someone had to clue me in, but instead of plugging, crimping, or otherwise disconnecting the vacuum line under the car, just unplug the actuator in the trunk in front of the drivers side tail light. I was a little unclear as to how this works, but it's dead...

Anyone elso can second Hyper's experience? I unplugged mine yesterday and first noticed no sound difference, but after a few highway miles I definitely think that the exhaust sounds deeper and lower (meaner). I also have a subjective feeling that the car is somewhat minimally quicker but it's probably in my head. who cares though? So if the unplugging causes no malfunctions I am inclined to leave it unplugged.

Makes sense about the cats warming up--the exhaust sounds the most agressive with the mod at cold startups. I'm not sure that this will cause damage to the emissions equipment--but it certainly will cause more emissions to be released while they are warming up.

I wanted to try this, but after HyperM3's post, I'm worried.

I'd like to see if anyone else who has unplugged theirs finds any problems.

if nothing happens for a while, I'll try it out.

I have had it for over a month ...no probs. That sounds like a lot of bull poooooo.

I wouldnt go that far as to say its bull poo, but I also did say my issue was probably a coincidence. Though, like I said, I dont need to add insult to injury by giving my car any other ways to crap on itself. I think the car sounds just fine stock. If I really wanted to hear the vroom vroom Ill pony up the cash for a legit exhaust.

I've had the mod on my previous e46 for years and currently on my e90 with NO problems at all. I advise the ball bearing or pellet method. Disconnecting electrical equipment on a car as advanced as this is a no-no. No matter what it is.

Just horsing. Your luck has been some what mysterious. I am eyeing the Borla. Had Borla on a Trans Am LS years ago. Like there stuff.

Thats the only exhaust I would consider at the moment(and really did). But I decided that new wheels and tires would be beneficial to me. Hence bringing up the topic of this thread.

which method did you use: the unplugging or the golf tee?

You Said "Vroom Vroom"...

I am certainly NOT going to say that the unplugging of the actuator is harmless, I dunno. But for the life of me I cannot imagine how a little flapper valve is going to either:

A: Get the cats hot faster.
B: Significantly increase back pressure, more importantly I mean how would an increase in back pressure heat a Cat Faster?

Regardless, it's important to note that we are tinkering with OEM stuff and while it seems harmless it could have some unknown effects.

I'm glad I took my time on this post to read it all the way through... After reading the first page, I was considering it. But after the 3rd page, Why risk it for such a small gain (more Vroom Vroom)?

Do aftermarket catbacks have a flapper valve? if not, then those running the catbacks should have a bunch of error codes recorded in the ECU, right? Or does the ECU only detect the unplugged actuator?

ECU only records the unplugged actuator. This is because youre breaking the electrical current to that solenoid telling it that theres a problem with it, ergo storing a code. However, if you just plug up the line with the BB or pellet or whever, it doesnt see it as a break in current, probably doesnt even know if its open or not. Its the vacuum that closes and opens the valve.

Give it shot on a cold start morning, preferably in a garage.

Start the car and listen for a few seconds. Then Shut it off and and unplug the wires shown in the first post. THEN start it up again, keeping in mind what it sounded like a second ago.

Enjoy the new growl... Is it worth some error codes that nobody is going to worry about most likely? I dunno you have to answer that for yourself. But it's worth listening to. The change though minor is very pleasant, all rorty and sounds heavenly in a parking garage etc.

Because we all know... (It's all about the VRoom VROOM)...

This is going to be my legacy isnt it...

I agree with you... unplugging the hose will not give an error because the computer is still sending signals to the actuator to close the valve and when it gets the pressure (hose tied up, golf tee) it sends a message back saying its closed thus no computer logging.
Too mnay factors also contribute to the issues I think people are getting; for instance the weather and altitute...here in florida we wake up with chilly 79 degree morning nowdays ;-) which does not require your cats to warm up much.

The cats get warmer by increasing the backpressure (less hot exhaust leaving at one time) so the hot exhaust fumes stay a bit longer in the cats warming it up faster. easy analogy...on your barbecue grill, leave the cover close, half close and open..you will see how the fumes escape (faster and slower) and also determines how hot it gets there to cook your food.. :-)

Potentially, but I was hoping it would be mine...

Cold cats FTW!

I tried this out.

and I didn't like it.

Thats too funny. I totally didnt even see that you had said it first. Great minds!

Ok, for S&G's I put one of my airsoft BB's in that line to see if there was a difference between the methods. All I did was start it up(its about 75° so its not too cold and I had just driven about 5 miles so it wasnt technically a cold start) and I think it sounded a bit deeper than with just pulling the plug.

I havent driven it yet, just started it, so Ill report back my findings later on.

UPDATE: Ok, so after two days of driving around I can categorically say that the mod is louder when you plug the line as opposed to just disconnecting it in the trunk. That being said, the drone at 2-2300rpm is there and can be annoying at times. Revving at stop lights is more fun but under hard acceleration cant really tell much of a difference. Havent really seen any change in mpg either.

confirming the mod works, the exhaust is louder and throatier but confirmed with my tech and longtran's claim that the car will lose some hp at top end, but if that is not minded, this works!!!!!!!!!!!!!!