Rattle under load

[stock5.7]

Hi guys got paccies and hi flow cats fitted a couple of weeks ago.
Problem is it's got a rattle when you back off or give it a good rev driving normal no rattle sounds good could it be the heat sheilds or could it be a cat it's also a vy a4 ss

Thanks Scott

[caaf]

Not knowing the setup, the car nor you I can only suggest is to get it dyno'd or at least ask the guy know you are trying to find a rattle.. As it would be handy to be able to walk around the car ect to source. Or hoist it up and start checking everything on the underside. No harm making a few phone calls ect.

[stock5.7]

Set up Car has inch 3/4 paccies with 2.5 high flow liverpool cats they told me with a 3.5 sureflo catback i have been under car all seems good .
The problem only appears when you take off with a bit of gusto then back off it rattles like the cat is loose inside or like heat shield is loose but driving in traffic it all sounds great if you dont push it .

Will take to a muffler shop in newcastle all work was done in syndey so was trying too save a trip .

[HYMEY]

dynoed????????put it on a hoist

[Wallace44]

I had a KPM exhaust fitted recently to my VE ute.

It had a similar rattle. Under the passenger side floor - the cat was just (like... only just) touching the heat shield.
When I got on her, the rattle would come - back off and it would disappear.

Could possibly be the same thing.

I took mine back to the shop, they replaced the bolt that holds the heatshield in with a rivet, and loosened headers - pulled down on the tail end of the header and then re-did all the bolts up. Rattle is gone after that.

[stock5.7]

Rear muffler has torn inside and noise is traveling along the pipes rattle problem solved new Di Filippo cat back installed very happy with note.:):):)

[whitels1ss]

Rear muffler has torn inside and noise is traveling along the pipes rattle problem solved new Di Filippo cat back installed very happy with note.:):):)
So it was a Di Filippo warranty problem?
How old, much work had it done?:confused:

[dgp]

Set up Car has inch 3/4 paccies with 2.5 high flow liverpool cats they told me with a 3.5 sureflo catback i have been under car all seems good .
The problem only appears when you take off with a bit of gusto then back off it rattles like the cat is loose inside or like heat shield is loose but driving in traffic it all sounds great if you dont push it .

Will take to a muffler shop in newcastle all work was done in syndey so was trying too save a trip .


So it was a Di Filippo warranty problem?
How old, much work had it done?:confused:

The guy stated that he had a 3.5" Sureflow cat back not a Difilippo

[Little Brad]

try your o2 sensors man

[whitels1ss]

The guy stated that he had a 3.5" Sureflow cat back not a Difilippo

Yes, thanks, I see that now, I missed that in his second post.:)
I only read his 1st and 3rd posts.:)