[sil_stang02]

Hey guys I just bought an 02 GT 5 speed on friday. It has 23K on it. But after test driving it I notices some rattling around the headers to the piping around 2K to 3K RPM. But didnt pay too much attention to it, I got a pretty good deal on it payed only 11K, so I was in a hurry to close the deal....

Anyways after looking the car over I noticed that it had no cats, just straight pipe to the Flowmaster mufflers...

1. Could no cats be the reason for the rattling???
2. Is there any internal damage that could happen due to having no cats?
3. Isnt there like a sensor down there that monitors the cats and assures that they are installed and working correctly?
4. Would it be just a simple job installing the cats? Sensors??

I mean what would you guys recommend, installed them or not? Rattling?

thanks, all comments welcomed please help...

[XtReMeLy Br0Ke]

Originally Posted by sil_stang02

Hey guys I just bought an 02 GT 5 speed on friday. It has 23K on it. But after test driving it I notices some rattling around the headers to the piping around 2K to 3K RPM. But didnt pay too much attention to it, I got a pretty good deal on it payed only 11K, so I was in a hurry to close the deal....

Anyways after looking the car over I noticed that it had no cats, just straight pipe to the Flowmaster mufflers...

1. Could no cats be the reason for the rattling???
2. Is there any internal damage that could happen due to having no cats?
3. Isnt there like a sensor down there that monitors the cats and assures that they are installed and working correctly?
4. Would it be just a simple job installing the cats? Sensors??

I mean what would you guys recommend, installed them or not? Rattling?

thanks, all comments welcomed please help...

is it a bolt-on offroad x/h pipe?

if so, check the collector bolts and the bolts on the rear of the h/x-pipe.

also check all the mounts of the exhaust...make sure it didn't slip off one of the hangers.


why are you wanting to put cats on there? they just decrease performance and make your exhaust quieter.

[OxMox]

+1... check all the bolts, gaskets, etc.

and DON'T put cats on it!

[jasonh_86]

don't put cats back on unless you have emissions testing.. just get some MIL's if your "check engine" light comes on and get under it and check the exhaust for any loose connections or anythin of the sort

[sil_stang02]

ok, Im sticking with no cats, since in this county I dont have to have an emission check... I was just told that not having cats could burn holes in my pipes..

But I will check all the bolts on the exahust, I havent had a chance to put it on a lift to really check all the bolts....

About the piping all I know about it is that its an H Pipe with 40 series flowmasters...

Also, my service engine soon came on yesterday.. I was told its more than likely the gas cap. Which the cap is kind of broke, will not lock all the way and seal. I just unhooked the battery this morning so it would go off. Any other concerns I should have about the light coming on?????

thanks guys

[sil_stang02]

Also, what are ML'S???

[bham_gt]

MIL eliminators = malfunction indicator lamp eliminators. They will keep your check engine light from coming on due to having no cats. They trick the computer into thinking that the cats are there and working properly.

[BlueRuckus]

Assuming that othing is loose, then the rattling that you're hearing is the exhaust resonating. I have the same setup, but with an X-Pipe and it does a bit of the same right around the same RPM that you mentioned. I don't know about burning holes in your pipe, unless you're running plastic pipes.

As far as the check engine light, you have 2 options.
1. you could get MIL eliminators, which are cables that plug into your H-Pipe and tell your computer that the change in exahust is OK.

http://www.partshopper.com/shop/Dall...9-04-m262.html

2. Or you could get a performance tuner, such as a DiabloSport Predator or a SCT tuner. This would be the preferred choice, and many members here would agree that this is a better investment. A tuner would be useful in the future when if you install gears or change your intake or for many other mods.

http://www.partshopper.com/shop/Must...ammers-43.html

Good luck and enjoy your stang!

[Fat Tony]

Im running a Mac Pro chamber w/ no cats into 40 serious flows. I occasionally get a rattle around the same RPM. On a few occasions I just get under the car and tighten the bolts at the collector and at the tail pipes. If your h pipe wasnt lined up right when it was put in, it could make the mufflers sit higher and occasionally bump the chassis. As for the check engine light you got to get the mil eliminators. There great and they will fool the emissions testing as well.

[DogVomit]

You won't burn holes.
The rattling could just be exhaust tremor, which is to be expected.

MIL eliminators plug right into the O2 sensors. You should have 4, but you only need to get 2, to plug into the back two O2 sensors. They're the ones furthest back.

If the Flowmasters are too loud, drop 'em and go with a quieter muff with the off road x.

[streetstang03]

the dealership prob. just cleared the code so customers wouldnt see the SES light on during test drives. If i were you, i would go to Autozone and have them pull the code that is tripping the SES light (they do it for free). If its coming on due to not having cats, just pick up a set of MILs and put them on. its simple enough to do.
Like eveyone else said, just get under the car and tighted everything up really well and see if that helps. the previous owner might just not have tightened everything up well enough.