Exhaust poping when idleing down

G

ga94gt

New Member

May 17, 2007

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Ringgold GA

Jul 3, 2007

#1

• Jul 3, 2007

• #1

When I rev up my car and it starts to idle back down it makes a poping noise. What causes this or do the 5.0 do this. It does it when it gets over 4000 rpms?

 

The Green GT

No 13 year olds are safe around me.

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Jan 8, 2006

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Jul 3, 2007

#2

• Jul 3, 2007

• #2

Mine did that when I had straight pipes. it still does it a little, but not bad.

When I had my straight pipes, if I would downshift and the tach would go to like 4K then it would sound like a shotgun. lol

 

G

ga94gt

New Member

May 17, 2007

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Ringgold GA

Jul 3, 2007

#3

• Jul 3, 2007

• #3

Yeah that is what is like got any idea's why?

 

S

steede302

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Mar 5, 2003

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jacksonville fl

Jul 3, 2007

#4

• Jul 3, 2007

• #4

My car did the same thing until I did a smog delete, then the sound went away. Never understood what removing the smog had to do with it, but it went away with the delete.

 

G

ga94gt

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May 17, 2007

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Ringgold GA

Jul 3, 2007

#5

• Jul 3, 2007

• #5

anybody else hae this problem? If so is there any way i can fix it?

 

R

RAD

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Jun 16, 2006

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Jul 3, 2007

#6

• Jul 3, 2007

• #6

haha that's funny, I have same problem , once I was in the first gear for like 10 sec. above 4000 rpms and when took foot off the skinny pedal it backfired so bad I thought something exploded. I have offroad H pipe and wasn't so bad but since couple months ago it started getting worst cause my vacuum leak(I think). Maybe is time to change o2 sensor ?

 

final5-0

Mustang Master

Apr 6, 2003

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DFW Texas

Jul 3, 2007

#7

• Jul 3, 2007

• #7

Popping on decel is usually excess fuel in the exhaust lighting off

Grady

 

GTA_V6_Mustang

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Nov 29, 2004

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Miami, FL

Jul 3, 2007

#8

• Jul 3, 2007

• #8

steede302 said:

My car did the same thing until I did a smog delete, then the sound went away. Never understood what removing the smog had to do with it, but it went away with the delete.

Click to expand...

Smog pump introduces fresh air into the cats to burn off excess fuel in the exhaust, which possibly explains why the popping noise went away after your delete.

final5-0
Popping on decel is usually excess fuel in the exhaust lighting off

Grady

Click to expand...

Pretty much the purpose of the smog pump, to burn off those extra hydro carbons to improve emmissions.

 

G

ga94gt

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Ringgold GA

Jul 3, 2007

#9

• Jul 3, 2007

• #9

So in other words it is no big deal all cars do it?

 

T

tderrick

Member

Oct 27, 2004

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Jul 4, 2007

#10

• Jul 4, 2007

• #10

excess fuel...

 

final5-0

Mustang Master

Apr 6, 2003

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Jul 4, 2007

#11

• Jul 4, 2007

• #11

ga94gt said:

So in other words it is no big deal all cars do it?

Click to expand...

No ... not really fair to say ... "All cars do it"

If you look at the basic operation of the Stang pcm ......
it has fuel shut offs to prevent that from happening on decell

and

Those shut offs help to save gas as well

My little 95 didn't do it when it was stock and it doesn't do it now

Grady

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Jul 4, 2007

#12

• Jul 4, 2007

• #12

Grady is right on, as always.
Even with no cats and 2 chambers, I get none of that thanks to the dashpot and decel strategy (or whatever its proper name is).

 

GTA_V6_Mustang

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Nov 29, 2004

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Jul 4, 2007

#13

• Jul 4, 2007

• #13

I never get credit for anything... lol.....