Hi Flow Cat Install DIY

[Shalviin]

Anyone have a DIY for a high flow cat install on a 2009 SRT-10 coupe? I am good up until the sides are off and the mufflers are off. Also, any recommendations for the cats? Thinking of ROE ones for like 700 bucks. Thank you in advance!!

[Steve M]

I never took pictures when I did mine, but the hardest part of mine was getting the side sills off...after that, it was pretty straightforward. The v-band clamps will require some persuasion to pop off, but once they are off, everything else should come out. The mufflers also took some persuading, but they came off and went back on fairly easily. About the only thing I had to do was expand one of the high flow cats (driver's side) because it was not slipping over the v-band flange properly. It should be tight, but this was too tight. Nothing that a cheap Harbor Freight exhaust pipe expander and an impact wrench couldn't fix though.

Make sure you take note of the angle and front-to-back location of the exhaust tips before disassembly...when you go to put everything back on, getting the tips in the right spot is the most critical part of the install. Fully cold, the exhaust tips should be forward in the opening...they'll expand and move back a good amount (like 0.75"-1") when the car is fully warmed up. You should really let the car get nice and hot to verify everything is where you want it before tightening everything down and reinstalling the sills.

Work on one side at a time so you have the other for reference...you may not need it, but it has sure saved me many times.

Also, if you have any desire to change out the sheet metal screws that hold the bottom of the side sills in place, this would be the time to do it. Many of us have switched to threaded inserts with machine screws since the sheet metal screws tend to strip out over time.

[Steve M]

Here are a couple threads about the threaded inserts for the side sills...the first thread is the most relevant, but there is some pertinent info in the second link as well:

https://driveviper.com/forums/thread...hreaded+insert

https://driveviper.com/forums/thread...hreaded+insert

[Shalviin]

Here are a couple threads about the threaded inserts for the side sills...the first thread is the most relevant, but there is some pertinent info in the second link as well:

https://driveviper.com/forums/thread...hreaded+insert

https://driveviper.com/forums/thread...hreaded+insert

Thank you for the awesome info!! I already have the side sills and catback out, so I guess the tough part is done. :-)