I have a 2005 S-Type R

I did the Magnaflow cats, 2.25 x-pipe exhaust.

I left the stock mufflers in and it sounded like a 1983 toyota corrolla. It was terrible. I changed the mufflers over to flowmaster. Now it has a great tone but its too loud. I am going to quiet it down somehow.

But even with the new mufflers, it still has this annoying pop sound in the exhaust under load. It got a little better from the new flowmasters but you can still hear it. Have any of you ran into this before?

Is it the x-pipe? if so, could removing it and putting some sort of two in two out muffler could help rid the pop and quiet it down?

I love the car but wanted it to sound just a bit more aggressive. Now it sounds like a mustang. I wanted AMG.

 

It'll be tough to get it sounding like an AMG exhaust, that's a specially tuned performance exhaust made specifically for that car.

However, many of us opted to run the 11385 magnaflow tru-x resonator in place of an x-pipe. It acts like an x-pipe but is muffled somewhat to bring the sound to a tolerable level. On the highway at cruising speeds I can't even hear the exhaust.

 

Okay, Right now its a magnaflow 10790 x-pipe, I will look into getting a 11385. I have to take it back to the shop anyways to get tips put on, they didn't have the right size in stock.

 

I have the same setup as you do minus the stock REsonators with the Magnaflow CATS, 10790 x-pipe, magnaflow mufflers not Flowmaster and 4" tips. I have no popping sound like you mentioned under load, just you hear a tad bit when you let go of the gas pedal, but thats normal....

Are you using the stock Resonators? & What size tips are going with if I may ask?

 

They didn't have tips in stock, so right now its just straight out of the mufflers until they come in. I believe they will be 3" tips. I do want it quieter so i might switch to the other instead of x-pipe. Right now its 2.25 throughout.