I run the following performance mods on my 07 lexus is350, I have a lot of life left on the car 66k miles so I decided to upgrade the exhaust accordingly:
- PPE Headers
- RR Racing Tune
- Invidia Midpipe
- Manzo Exhaust (similar tone to Invidia Axleback, budget version)
- No Cats

After all of these mods, I have a terrible rasp especially during the WOT position. I have determined the rasp is coming from the invidia midpipe. However, before removing all of the cats, the overall tone of the car was great. I am debating on the proposed mods, but I want to make sure I achieve no rasp and deep tone without creating a money pit. I was looking at sound clips, and the tone I'm aiming for is captured by the following sound clip of a Lexus ISF with PPE Headers (catless), Borla Catback + Bazooka muffler delete. The tone is amazing with little rasp.
OPTIONS:
1) Install PPE High Flow Cats ($400 cost, $100 labor estimate + $300 part). However, I'm unsure if this will clean up the rasp without taking away the tone of the resonator. On the plus side, this will eliminate the foul odor. I am leaning towards this route because before the PPE Header install, my exhaust sounded great, it became extra raspy once the primary cats were removed... On the downside, I will see a slight decline in performance.
2) Replace Invidia Resonator with another brand that gives an aggressive, deep, clean tone. However, I'm unsure of a good replacement. I don't see any sound clips of a setup on youtube with PPE Headers, catless, and a different type of midpipe. Common setups include either Megan Racing or Invidia. I was looking into Borla resonators but not many promising results are out there. Any suggestions?
3) Resonator Delete. This will altogether remove the rasp, however, I'm unsure what the tone of the car will sound like. Any suggestions?

I'm a little hesitant with proceeding with any of the above options and I am open to perspectives!

 

Nice, but wrong section. This is for the first gen 2001 to 2005.