My 04 rx8 MT is.. or was a clean car at one point. Its been sitting for the past few months because i started having a few issues and wanted to take care of everything at once.
-My CEL is on and dark suty smoke comes out after high rpm I ran it on the OBD scanner and it came up as an Evap problem so I'm guessing the o2 sensors since this seems to be the most commoon. First question is how can I tell which sensor and or both for that matter.
If that is the problem i need o2 sensors so anyone that has any for sale please let me know. I
-Im looking to buy tires,exhaust ect. so anyone who is out in Orange County should hit me up if there parting out so i can hear what you have.

First, can anyone offer me insight into the o2 sensor problem im having?

Cheers!

You need the code nuber the scanner gave you then you can search the sight using the code. If it was an o2 sensor then the scaner will tell you that is was an o2 sensor. An evap problem is not an o2 sensor problem. It could be as simple as a cracked vacuum hose.

ok awesome. Im going to get that tonight. i'll get back to you and let you know exactly what came up !

P0442 usually = gas cap. take it off clean it real well and clean the neck as well.
Some have had to actually replace the cap.

Now.............black smoke after high RPM's? how much and anything else wrong?
If you get an o2 code when it's read, then I would drop the CAT and take a look to see if the honeycomb is still intact. If not, then know that the CAT is covered for 8 years or 80k miles, so go get a new one!

Might want to do a search here using advanced search and look up "Seafoam", might be time for a good cleaning!

How many miles on this car?
How old are the plugs(in miles)
Have you ever changed the coils.....how many miles on them?