I was using regular gas in my 8 and the check engine came on. someone told me to start using premium gas to fix it. The 2nd fillup of premium and it went off. Ive continued to use premium and in the past month, its came on and went off twice. It'll stay on for 2 or 3 days then go off. Any ideas on why it would be doing that? Thanks

without knowing the exact CEL code it will be hard to offer advice.

I believe it was P2096

A search brought up this thread http://www.rx8club.com/showthread.php?t=162627

How many miles on your 2004? You might just need either a MAF or o2 sensor, both are easy to change.

i would check my engine.

p2096, i'd suspect an intake leak somewhere. the freezeframe data would be super handy as we could see what fuel trims the car is seeing, as well as a log of the rear o2 sensor which could be out of whack and reading way out of spec.

kevin.

Hi Teknics,
I didn't get that stuff about freezeframe data (but the song popped into my head). I'm guessing it's something the dealer would do?
I replaced the rear o2 sensor in Dec. and the ig. coils in Nov.
Last Saturday, after 2 hours of driving on the interstate, the CEL came on , reading 2096. What is my first step?
Thanks, Paul

Check for intake leaks.
Coils may ned to be replaced.
If you get the code again after fixing tese two then its the O2 sensor.

Don't worry about it Paul unless the code pops up again with another cell.

But do check for intake leaks.