Catalytic converter discoloration

[Pokey]

This look familiar to anyone? I’ve tried polishing to no avail..

[MV8]

It looks like a cleaner was dripped on the hot exhaust and removed some of the finish. The gold color is a coating.

[11Budlite]

On 9/11/2024 at 11:11 PM, Pokey said:

This look familiar to anyone? I’ve tried polishing to no avail..

 

 

That looks just like mine too. I haven't done anything to improve the appearance yet, but from research it seems like it can be polished. A fair amount of effort is involved though: https://www.caterhamlotus7.club/forums/topic/266489-exhaust-polishing/

[Vovchandr]

Hard to tell but it's one of two options. 

 

1) if it's a coating you'll need it refinished

2) if it's natural color from heat then whatever is on there can be polished off 

[CatManDo]

There is no coating on the cat. It comes just polished stainless like the pipes. The color is just normal heat coloration. Anything from the road that gets splashed on it while hot will remove the color like that.  If you really want to remove it use a product for removing blue from chrome motorcycle pipes. Those products work just fine on stainless too. Mine look like crap after 900 miles in the rain.

[CBuff]

After last weekends track day I did a deal clean and started wondering about the exhaust.  My car was new in June and the exhaust slowly turned blue and now a bronze with some of those colored spots on the collector. Well went down the rabbit hole on polishing. It was fairly straightforward and worked well. 
 

before:

 

after

Loosened the heat shield to access the cat.  
 

used this:

 

Flitz Buff Ball Car Buffer Drill... https://www.amazon.com/dp/B002RCVQM0?ref=ppx_pop_mob_ap_share

 

even with the drill buff ball took some elbow grease but not horrible. Buffed with soft plush micro fiber. I also got some smaller buff balls for in between the primaries. 
 

[CBuff]

[11Budlite]

That came out really nice!