How To Polish Your Cat Back Exhaust

Posted by on April 20, 2008 - more

I have a Borla cat back and I polished the exhaust from where it bolts on right behind the pumpkin. Its all that you can see of the exhaust. Mine separated at that point so it made my life easier. Yours may not depending on what you have. Also different metals may polish faster/slower too keep this in mind.


Items Needed (Total cost should be around 20 dollars)

  • A set of rubber gloves (good flexibility) as the sanding residue is a pain to wash off.
  • 300 Grit Sand Paper 1 package
  • 400 Grit Sand Paper 1 package
  • 600 Grit Sand Paper 1 package
  • 800 Grit Sand Paper 1 package
  • 1000 Grit Sand Paper 1 package
  • 1500 Grit Sand Paper 1 package
  • 2000 Grit Sand Paper 2 packages
  • A bottle of water (spray bottle if you can) to keep the pipe wet for wet sanding
  • Something to wrap your tips in to keep them from becoming scratched.
  • Metal Polish
  • If possible some sort of electric buffer for the final shine
  • Tools to remove and reinstall your catback (each is different so look to see what you need here)
  • You can also pick up an extra pack of each sand paper just to be safe as you may need it. In a normal 6 sheet pack from 3M I used 3 sheets (torn in half so 6 parts) for each pipe.

Sand paper I Used

Level of Difficulty
On a 1-10 this job gets a 2. The hardest part is taking the exhaust off. Expect to take around 7 hours to be done. I started at 1pm and finished at 8pm.

Step 1 – Remove Exhaust
Use ramps or jack stands, what ever you want to get the exhaust off. I would highly recommend wrapping the exhaust tips in something to keep them from becoming scratched, it is very easy to scratch them. The stock rubber hangers are the hardest part of this. If you can get them started you can wiggle them off, it just takes a good bit of time. Try to pull down on the exhaust and pull put and shift the hanger back and forth. This little spawn of Satan can be tricky. Don’t throw things if you can help it. After you have the exhaust removed its time to clean them up and sand!

Step 2 – Clean up the exhaust
Clean up the exhaust pipes good to remove nasty road grim

Step 3 – Sand with each level of sand paper
Before you start make sure the tips of your exhaust are protected, as you move the pipe around they may become scratched as mine did. Don;t repeat my mistake. Keep the pipe wet and wiped off as you sand. It makes a mess either way and the stuff that you sand off does not come off easy on what ever it gets on. Be careful where you sand your exhaust at. Take the sand paper pieces and tear them in half and use half of in about 6 inch increments down the pipe keeping an eye on the paper to see when it is used up, Keep it flat for the best results. Use a up and down and side to side motion (circular). Take your time as this is the base of it all and keep the area you are working on clean and wet. Pay attention to how the metal looks after its sanded, you want a uniform pattern all the way. Clean the parts up good before going on and regularly while sanding. Once you are done going in small circular motions go back over the pipe in a straight direction to remove the swirls before moving on to the next level. Make sure you take your time here and don’t hurry through this step. This needs to be the final thing you do between each sanding level.

400 Grit Sand vs Stock Pipe cleaned up

Step 4 – Sand with 1000 grit
Do just like 300/400/600/800 grit, take your time and sand the entire part. It wont be as easy to see where you have been so keep tabs on to what part on the pipe you are going in each 6 inch increment. Clean the parts up good before going on. You can start to see the shine that’s slowly coming out by this step.

1000 Grit vs Stock Pipe just cleaned up

Step 5 – Sand with 1500 grit
Do just like 1000 grit. Start taking a little more time here to bring out the sine good. Clean the parts up good before going on.

1500 grit vs 1000 Grit

Step 6 – Sand with 2000 grit
REALLY take your time here spend twice as much time as you did with the 1500 grit. Make extra efforts to sand the areas that will be seen the most when installed back on the car.Clean the parts up good before going on. If you did like I said and removed all the swirls at the end of each step and took your time you should really start to see a nice shine, the foundation is key here.

2000 Grit (Dirty tough looks better cleaned)

Step 7
Use some really good metal polish and apply some by hand. Do a couple good coats and let it sit for a couple of minutes and buff it off. I do not have an electric buffer or drill so the images below are before this step.

The end results of all the hard work!

Step 9
Reinstall the exhaust and align as needed, finish off by wiping down the exhaust pipes. Make sure your tips are covered. Mine were not and became scratched here. Don’t repeat my mistake.

That is all it takes, the finished results:

Please note these changes while they look good were done with skipping to many levels of sand paper. I have since redone it in slower steps of moving up in sand paper and it looks much much better.