Im having alot of problems with my girls 2004 mazda 6.it keeps pulling the p0138 code witch is o2 sensors i just replaced all of them along with all 3 cats,spark plugs aswell as a couple of vac lines but it still runs really ruff when you try to take off but it gets better when you let off the gas just a bit the light keeps coming on showing p0138 even tho its new ive reset the code i dont know what else to do is this a computer problem?

 

Two tother things may be causing this problem... that I know of from experience.My car acted this way when I had:
1) A bad or dirty MAF sensor.
2) A stuck or clogged evaporative purge valve.

You don't say whether its a 4 or 6 cyl. And if your gf is filling the tank up to the top (overfilling) that too can cause trouble w/the Evap system.

 

Its a 3.0 v6 ive cleaned the MAF and it didnt help so it could in fact just be bad.im not sure where the EPV is located your talking about if you could give me a heads up on it id be greatfull.

 

I tried cleaning the MAF before replacing it too, but it didn't help.
On my 2.3L 4-cyl, it's right up front-center near the the throttle body, but I don't have a clue where it might be on the V6. 'Probably close to the TB since it feeds fuel from the evap system back in to be burned.

Sheldon? Anyone?

 

so i pulled a vacuum line frome the back of the trottle body and its wet with fuel im not sure where this valve is that you mentioned is it on the throttle body or an inline valve?