I have an 04 rx8 with 59k on it and I had the CEL light come on a couple weeks ago. Went to auto zone and had the code pulled and it was the gas cap. So I replaced it with their aftermarket one and now the CEL came on again. Went to auto zone and had them pull it and it was the same problem. Air and dirt in the fuel system. Do i need a gas cap from mazda to fix the problem?

 

^ its comon with our car. same thing happened to me. just turn the gas cap a few times (clicks) i do like 7-8 clicks.

 

How long does it take to clear that code?

 

It takes a few 'drive cycles', wait till the weekend it should go away.

 

should i put any fuel system cleaner through it?

 

No need to, when I replaced my gas cap it took a day or two for the light to go away.

 

My concern is that the CEL went off last week when i replaced the gas cap...but it's now on again and tripping the same code.

 

yeah it will go off in like 2 days or so when you put fresh gas and stuff.

 

ok good....god that thing is sensitive

 

Spin the cap a half dozen clicks after refueling; believe it or not it makes a difference!

Autozone and similar used to reset the code for free, or a friend with an OBDII device.

 

It takes exactly 4 engine on/off cycles to clear the CEL. I randomly got this issue prior to fastening the gas cap with 7-8 clicks before engine start.

 

If it still doesn't go away then you have a leak somewhere in your evap fuel system. The engine draws a vacuum on it when you start it, and if it doesn't hold it trips the CEL. It may not be the cap at all. It could be something like a vent hose or the gasket around the fuel level sending unit.