View Full Version : 05 STS Exhaust

05-28-09, 08:42 PM
05' STS AWD V8... check engine light codes back to the catalytic converters. Any help as to a "non" traditional fix. Why replace with stock cats if I don't have to only to have them fail again.

Angus Young
05-28-09, 09:00 PM
I have the same problem, dealer wants $2000.00 to replace them as they are 1 piece unit with the exhaust manifold, I have looked for headers but as of now I still havent found a solution, the cats arent clogged they just are not as efficiect as they were when new, I have about 17,000 miles on my engine light, low efficiency cats, but I still do about 21 mpg on the hiway and I can tell you recently I have seen 140 on the heads up...
If you take it to your local muffler shop they can install hi flow cats as replacements, let us know how you make out as I believe most of us will be looking at this same problem, I am currently at 131,000 milez and always use BP 93 Ultimate premium fuel

BlackedouT STS
11-24-09, 01:01 PM
any solution yet? I believe I am having the same problem and my remote start wont work with the CEL on.