With just the catback, I had some exhaust burble when letting off the gas. Now, with the header, I have LOTS of burble... to the point of being a bit distracting. Like if I'm driving steady speed at part throttle even. Is this a sign of anything wrong? Maybe just a really crappy stock JCW tune? Doesn't seem like I should be getting that much grgehrjywvctftf4ec from the system.

 

dont forget, a header will make an exhaust louder. I had a 79 f150 4x4 with a flowmaster dual exhaust that sounded rel mean, threw on headers and it sounded like a real loud tin can sound.
What system are you running, I love the burbling sound it gives it that bad *** sound.I only get it when i hit about 3500 rpms with my borla and wish it were more often and just a little louder.
I heard a skunks works exhaust that had a nice burble sound to it but i dont know the price or the HP gains. I know the borla only gives a miniscule 5-6HP increase.

 

ALTA header, Milltek catback.

The system definitely got louder after the header went on, but it's also making a lot more of the "junky" noise, and that seems to be coming from the catback area - under the car. Just wondering if the larger header pipes affect the flow to where it makes weird things happen in the pipe, or maybe the lack of a pre-cat allows more unburned fuel to make it back into the pipe where it pops. Or, as I said, maybe it all works great together and my stock ecu just really has the mixtures and/or timing way off.

 

your just getting more of an echo sound now. I wouldnt think anything was wrong. the headers + the open free flow cat + open exhaust is going to make your system a lot louder and burble more as well. its an open non restrictive set up.

 

"grgehrjywvctftf4ec" just really struck me as funny! Thanks for the laugh.

FWIW, my burble has NEVER "grgehrjywvctftf4ec" at steady speed. THAT does NOT sound right. Unfortunately, I don't know what might cause it.

The Alta guys seem to be pretty good about customer support. Maybe you should ask them.

I have a Milltek catback with OBX header and OEM cat, installed in the same order you did yours. The addition of the header only marginally increased the overall loudness, but I guess it made enough difference so that a previously unnoticeable sound would suddenly become noticeable.

Good luck.

 

Now thats FUNNY as if there were order options .

 

I meant I first had the catback installed, THEN had the header replaced.

See, it's not THAT absurd, eh?

 

Not absurd at all - Still FUNNY thou

 

You should try an ECU reset. When I put my Magnaflow Catback on I was getting a lot of strange burble, it smoothed out considerably after I reset the ECU (w/OBC). The lack of the precat with a high flow Cat is probably enough to effect the AFR.

 

I guess its worth a try BUT the ECU should automatically adjust via the a/f sensor reading should it not?

My set-up - obx header, recycled cat and obx catback didn't do anything strange. My burble is most affected by the weather - on cool days I have more than hot days.

 

[quote=Bahamabart;1990772]... BUT the ECU should automatically adjust via the a/f sensor reading should it not? [quote]

Yeah, but I think it uses the adaptive settings to adjust the AFR. The reset should allow it to have a fresh start.

 

I'll give that a shot. Thanks for the suggestion.

 

can you reset the ECU by disconnecting the battery for a period of time?

 

Sure, I feel it's easier to use the ODO button though.

 

Pardon me for asking.... But how do you reset the ECU via the ODO button??

 

The ECU (and its adaptive learning) CANNOT be reset through a battery disconnect, or dash controls. Those procedures only reset the OBC (On Board Computer), not the DME (Digital Motor Electronics - AKA ECU).

The DME can only be reset or updated through use of BMW's computers (or a compatible system ala Dimsport).

- Matt

 

It worked for me, without a doubt.

 

Placebo effect.

No joke, I had run this by a Mini tech, so unless he was misinformed or lied to me, battery unplug does the same thing as dash reset, that is, to reset the OBC and OBC only.

I have also read to this effect on the Mini2 forums as well.

- Matt

- Edit -

See these threads/posts:
https://www.northamericanmotoring.co...ight=ECU+reset
https://www.northamericanmotoring.co...28&postcount=5

 

NO "Placebo effect.".

The car was having all kinds of trouble maintaining stable AFR. It was "hunting" all over the place, idle was rough and the exhaust was shacking a lot. I ran this procedure, restarted the car and it ran smooth as the day I drove it off the dealers lot, with stable 14.7 on the AFR gauge at idle. I don't care what some (even mini techs) say, It works on my '06 ECU. If yours is pre '05, then maybe not.

https://www.northamericanmotoring.co...ight=ecu+mini2

 

Your link agrees with me, that it's OBC only. See post #16 by Partsman, and post #22 by Barnabas...

Saying you don't care what Mini techs and the facts say shows willful ignorance of said facts.

I don't know what could have changed these things for you, but I can essentially guarantee it wasn't resetting your dash computer that did it. I'm not denying that things got better around the time you did an OBC reset, I am only making that point that doing that most likely had nothing to do with the improvement.

Not trying to be a tool, just pointing out facts.

- Matt

 

Techs don't, and can't know everything. Most if any have never tried this procedure, why would they. They're gonna hook up to the OBDII port and do there work there, especially if they suspect a problem that could be diagnosed/fixed through the ECU.

The improvements didn't take place "around" that time. It was immediate, 1 minute had passed and the change was like night and day. I had a problem and this fixed it, I have no doubt.

 

{interupts bickering}

Brian has the extra volume lead to some more spirited driving? On the stock system I've noticed a ton of steady state burble is directly related to how warm I've gotten the engine, the more I push it the more burble I get. Of course I'm on an 05 so the tune is different for increased but if the added stock restriction offsets a portion of that I wouldn't say it's out of the realm of possibilities. Of course I could have something wrong too

{/resume bickering}

 

Oh, I was done.

- Matt