Modified Exhaust

Hivand_M · 07-15-2021, 12:44 PM

Hi All,

Have you noticed your exhaust tone is different each time you start your car and drive it? (not talking about cold start's sound)

What I mean: during the week, i'm at work all day so the only time I drive my car is early AM and again after 6pm-ish. I've noticed the tone of my exhaust sounds tame and very nice with these commutes to and from work, basically right after a fresh cold start (car has been sitting for hours).

But let's say I need to get gas after work before going home. If I cold start my car after work, have a nice sounding exhaust tone to the gas station, turn the car off, etc. Now when I turn my car on for the second time, the tone now is SO much louder/crazy bassy and doesn't sound as good. It becomes obnoxious.

This isn't only on short drives, happens with short or long drives where I turn the car on, off, then back on.

Setup: AA rear & oem x-pipe with test pipes
(would notice this prior to test pipes as well)

Ajolives · 07-15-2021, 01:29 PM

Yea, happens to me. I have the same exhaust and never really questioned it too much. Just assumed it's the O2 sensors and adaptations being wonky; Cats are already warmed up, but the car still seems to want to cold start.

Hivand_M · 07-15-2021, 01:31 PM

Quote:

Originally Posted by Ajolives

Yea, happens to me. I have the same exhaust and never really questioned it too much. Just assumed it's the O2 sensors and adaptations being wonky; O2 sensors are already warmed up, but the car still seems to want to cold start.

Interesting, yeah kind of sounds like you're driving with cold start still going on.

Is yours tuned?

Ajolives · 07-15-2021, 01:34 PM

Quote:

Originally Posted by Hivand_M

Quote:

Originally Posted by Ajolives

Yea, happens to me. I have the same exhaust and never really questioned it too much. Just assumed it's the O2 sensors and adaptations being wonky; O2 sensors are already warmed up, but the car still seems to want to cold start.

Interesting, yeah kind of sounds like you're driving with cold start still going on.

Is yours tuned?

Yup, exactly and takes a bit longer to calm down even when driving. I'm not tuned at all, still have primary cats in place. If/when I tune I'd probably just delete the cold start.

Hivand_M · 07-15-2021, 01:40 PM

Quote:

Originally Posted by Ajolives

Quote:

Originally Posted by Hivand_M

Quote:

Originally Posted by Ajolives

Yea, happens to me. I have the same exhaust and never really questioned it too much. Just assumed it's the O2 sensors and adaptations being wonky; O2 sensors are already warmed up, but the car still seems to want to cold start.

Interesting, yeah kind of sounds like you're driving with cold start still going on.

Is yours tuned?

Yup, exactly and takes a bit longer to calm down even when driving. I'm not tuned at all, still have primary cats in place. If/when I tune I'd probably just delete the cold start.

Oh gotcha but after the second start mine does not calm down, ever. I also never take off until cold start is over.

Curious if this is just how the s65 is.

Ajolives · 07-15-2021, 01:45 PM

I typically don't take off until cold start cycle finishes either, however I make an exception for when that happens just cause I know it won't calm down until I start driving. Also, may be unique to AA, not sure if any others have the same issue. Maybe something with the canisters….not sure.

ShaunT123 · 07-15-2021, 04:15 PM

If your AA rear section is new then that could be the culprit, I know a few people have experienced something similar until the exhaust got a couple thousand miles on it. - it could also be an exhaust leak, I noticed some weird resonance and it ended up being a leak between the x-pipe and rear section, check the clamps maybe?

NascaBmw16 · 07-15-2021, 04:51 PM

Same here. My M3 (e90) 2011 ,was tuned by the previous owner and had cold start delete, windows will go down 1/4" when opening front doors ( like coupe does),angels eyes will come on when unlocking the doors . So my FRM went bad two weeks ago ,i took it to the bmw stealership ,they replace it at no charge (under warranty) and now car is acting weird. Comfort access doesn't work, windows don't go down 1/4" anymore,angel eyes don't turn on when unlocking doors,car is super loud when first start (cold start)wait 10 min, drive around the block turn off engine ,turn back on again and is like starting the car from the beginning, super loud.

07-15-2021, 12:44 PM	#1
Hivand_M Private First Class 138 Rep 193 Posts Drives: E92 M3 Join Date: May 2021 Location: Los Angeles iTrader: (2)	Modified Exhaust - Does this happen to you? Hi All, Have you noticed your exhaust tone is different each time you start your car and drive it? (not talking about cold start's sound) What I mean: during the week, i'm at work all day so the only time I drive my car is early AM and again after 6pm-ish. I've noticed the tone of my exhaust sounds tame and very nice with these commutes to and from work, basically right after a fresh cold start (car has been sitting for hours). But let's say I need to get gas after work before going home. If I cold start my car after work, have a nice sounding exhaust tone to the gas station, turn the car off, etc. Now when I turn my car on for the second time, the tone now is SO much louder/crazy bassy and doesn't sound as good. It becomes obnoxious. This isn't only on short drives, happens with short or long drives where I turn the car on, off, then back on. Setup: AA rear & oem x-pipe with test pipes (would notice this prior to test pipes as well)
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07-15-2021, 01:29 PM	#2
Ajolives Captain 922 Rep 933 Posts Drives: E90 M3 Join Date: Mar 2019 Location: Tampa iTrader: (0) Garage List 2019 Audi SQ5 [0.00] 2008 BMW M3 [0.00]	Yea, happens to me. I have the same exhaust and never really questioned it too much. Just assumed it's the O2 sensors and adaptations being wonky; Cats are already warmed up, but the car still seems to want to cold start.
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07-15-2021, 01:45 PM	#6
Ajolives Captain 922 Rep 933 Posts Drives: E90 M3 Join Date: Mar 2019 Location: Tampa iTrader: (0) Garage List 2019 Audi SQ5 [0.00] 2008 BMW M3 [0.00]	I typically don't take off until cold start cycle finishes either, however I make an exception for when that happens just cause I know it won't calm down until I start driving. Also, may be unique to AA, not sure if any others have the same issue. Maybe something with the canisters….not sure.
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07-15-2021, 04:15 PM	#7
ShaunT123 m3>financial security 76 Rep 103 Posts Drives: F80 M3 Join Date: Jan 2021 Location: Los Angeles, CA iTrader: (3)	If your AA rear section is new then that could be the culprit, I know a few people have experienced something similar until the exhaust got a couple thousand miles on it. - it could also be an exhaust leak, I noticed some weird resonance and it ended up being a leak between the x-pipe and rear section, check the clamps maybe? __________________
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07-15-2021, 04:51 PM	#8
NascaBmw16 Private First Class 39 Rep 171 Posts Drives: M3 E90 Join Date: Oct 2019 Location: Pompano Beach,FL iTrader: (1)	Same here. My M3 (e90) 2011 ,was tuned by the previous owner and had cold start delete, windows will go down 1/4" when opening front doors ( like coupe does),angels eyes will come on when unlocking the doors . So my FRM went bad two weeks ago ,i took it to the bmw stealership ,they replace it at no charge (under warranty) and now car is acting weird. Comfort access doesn't work, windows don't go down 1/4" anymore,angel eyes don't turn on when unlocking doors,car is super loud when first start (cold start)wait 10 min, drive around the block turn off engine ,turn back on again and is like starting the car from the beginning, super loud.
	Appreciate 0 Quote