olivier753

Hello guys, after bad problems with my esp module unit a new one Now lol, i have a custom exhaust and the Resonator delete on my MB so the car singing very Well and loud, three days ago i notice my car make some very low sound and also notice a little rattling sound when i press the gas pedal, nothing on the dashboard and nothing with the diag... Any ideas ?

illest

heat shield on the exhaust?

olivier753

No its not that , how can i check if its come from the first cats or the secondary ?

illest

if its from the cats I think you can get under the car and hit the cat with something and you should hear it rattle. When my cat went bad it would only rattle when the car warmed up.

olivier753

Thx for the advice ! Do you know where i can buy some high Flow primary cats that fiting with the w210 and the 02 sensor

snooozie

Check eBay. I had this one on my favorites in case mine break. item # 150404436033

olivier753

thx snooozie ! does it need to cut and weld? its not suppose to be 2.25" for the cat ?

olivier753

So 1.) cut the cats and leave that garbage inside (it was broken) weld it after,put the car on (Park mode) push the pedal no rattling and the sound Is now loud and good, but... When i drive the car everytime i push it, i heard a strongly rattling mettalic noise Resound behind the loud v8 sound during all time i accelerate .. Any opinions ? Thx

NAFT1

Does it rattle when you have it neutral and rev, then let off, or just when in motion?Rattle when stopped and while driving, your primary cats are going out, assuming that you only removed the two secondaries; if you are completely without catalytic converters, the plastic baseplate that is used to attach the exhaust hangers to the transmission is another big culprit. If that is the case, you can get them for $7 or so at ECS or others. If it does it only when driving, I'd say look at the flexplates on the driveshaft, and transmission mount as well.