Bad flat spot/exhaust rattle 1500-3000rpm

[wasthadon]

Hi guys, new to the forum and just got myself a 197cup, its had a centre box and 2nd cat removed as it says on an invoice it has, there seems to be a very bad flat spot between around 1500 up till 3000k where it just splutters and rattles and something sounds like its moving or loose underneath. But after 3k it seems fine and feels normal with and nice little bit of pull to it.
To be honest i hate the way it sounds overall, very raspy just sounds ridiculous. The car has apparently just had the manifold welded as it had cracked, but it does sound like the exhaust is hitting off something maybe the welding has caused it to hit of the subframe?

So is this flat spot something that usually happens with the bits removed that 'mine has? And does it sound like something that could be mapped out?

And also im not sure if the invoice for the centre box removal and "2nd cat" removal actually means the normal cat or the pre cat as all thats written is 2nd cat so a bit confusing.

Here's a pic of her anyway, just got out of an r26 and into this [emoji23]

 

[Raptor6767]

The flat spot can be remapped out in most of the cases.

Removal of the 2nd cat usually means that the second (the first one is on the exhaust manifold) cat is removed.

 

[Kazumz]

Raptor is correct and it's usually because you've got one cat removed, the car throttles back or the AFR's are out as a result. STAY away from full throttle while in the flat spot as you never know, it could be causing damage.

Either put a cat back in, or get it mapped out.

 

[Pav]

as above mate..the flat spot does appear after the exhaust system has been messed about with..you can have it mapped out which i would suggest otherwise it will drive you nuts anic:
regarding the knock..try to check the exhaust middle mount..it may be damaged..

 

[wasthadon]

Cheers for the replys guys really is driving me nuts and sounds stupid tbh.
So would you guys recommend me getting the cat and mid box back on? Or would it be ok with just a cat put on it and leave the centre box removed? Would need to source the bits too as it didnt come with the bits that were removed.

 

[ShaunM]

Hi mate.Even if you put the cat back on the flat spot could still be there,due to the middle box delete.Got mine remapped.Really smooth now and more torque.plus you keep nice engine note lol.

 

[Kazumz]

Cheers for the replys guys really is driving me nuts and sounds stupid tbh.
So would you guys recommend me getting the cat and mid box back on? Or would it be ok with just a cat put on it and leave the centre box removed? Would need to source the bits too as it didnt come with the bits that were removed.

Put the cat back on first, then try it. Make sure to drive the car for a bit first. If not, put the silencer back on. My mate went from a Scorpion to Standard again and it sounded very ill, it needs a bit of driving to come back around.

 

[Pav]

cat back first if you want or you could look into getting an aftermarket system..lots to choose from and they are not that expensive anymore..remap afterwards i would say
check this thread:http://www.clio197.net/forum/showthread.php?22200-The-Definitive-What-Exhaust-Do-You-Have-Thread

 

[Ksykes23]

Could be rattling on the heatshield as well

 

[licenuk]

Hi guys, new to the forum and just got myself a 197cup, its had a centre box and 2nd cat removed as it says on an invoice it has, there seems to be a very bad flat spot between around 1500 up till 3000k where it just splutters and rattles and something sounds like its moving or loose underneath. But after 3k it seems fine and feels normal with and nice little bit of pull to it.
To be honest i hate the way it sounds overall, very raspy just sounds ridiculous. The car has apparently just had the manifold welded as it had cracked, but it does sound like the exhaust is hitting off something maybe the welding has caused it to hit of the subframe?

So is this flat spot something that usually happens with the bits removed that 'mine has? And does it sound like something that could be mapped out?

And also im not sure if the invoice for the centre box removal and "2nd cat" removal actually means the normal cat or the pre cat as all thats written is 2nd cat so a bit confusing.

Here's a pic of her anyway, just got out of an r26 and into this [emoji23]

Sorry to bring up an old thread but the rattle/noise/vibration you mention sounds like what I'm struggling with! Just wondered if you got to the bottom of it.
It's ruining it for me. It sounds terrible and I hate driving it as I have to keep it below 2k or over 3k to avoid the noise. Not always ideal!!

 

[Robert_197]

Sorry to bring up an old thread but the rattle/noise/vibration you mention sounds like what I'm struggling with! Just wondered if you got to the bottom of it.
It's ruining it for me. It sounds terrible and I hate driving it as I have to keep it below 2k or over 3k to avoid the noise. Not always ideal!!

I just had this problem my self. After having it on a ramp today with me revving it and a friend with a torch under it we found that the weld had split to the centre box. It was really small and took a while to find but it's definitely that on my car.

 

[Robert_197]

Clio 197 rattle when hot

 

[Foxspeed]

i have had it where the centre box is rattling and cause the knock sensor to retard the timing causing it to loose power

 

[Robert_197]

i have had it where the centre box is rattling and cause the knock sensor to retard the timing causing it to loose power

I'm thinking of deleting the centre box. What did you do?

 

[Foxspeed]

I'm thinking of deleting the centre box. What did you do?

the motor i worked on and found the rattle he got the silencer replaced

 

[Robert_197]

the motor i worked on and found the rattle he got the silencer replaced

I was thinking of just cutting it out and putting a straight pipe in but I've heard bad thing about flat spots on here. Still undecided.

 

[sevenfourate]

i have had it where the centre box is rattling and cause the knock sensor to retard the timing causing it to loose power

Having had a knock sensor issue during my remap mk1: I can well believe and sympathise with that !

 

[Foxspeed]

I was thinking of just cutting it out and putting a straight pipe in but I've heard bad thing about flat spots on here. Still undecided.

the centre box is a straight through type so not so much of a flat spot issue as its not really a restriction thats being removed

 

[Robert_197]

Having had a knock sensor issue during my remap mk1: I can well believe and sympathise with that !

Where is the knock sen

the centre box is a straight through type so not so much of a flat spot issue as its not really a restriction thats being removed

I would agree with you completely, but there seems to be quite a few people said don't do it because it will create a flat spot?!? Seems bizarre to me.

 

[Foxspeed]

Where is the knock sen

I would agree with you completely, but there seems to be quite a few people said don't do it because it will create a flat spot?!? Seems bizarre to me.

knock sensor is on front of the engine under the inlet manifold between cylinders 2-3