2000 S model idle issues

[Sdav86]

Hey everyone. I've been having issues with my boxster. I keep getting the two codes saying that the mixture is lean, but yesterday something different happened. I was stopped at a light and the idle started dipping down like I was running out of fuel then shot up to 2000rpm for a second then came back down. I've already replaced the maf and aos and also checked the oil cap. Could it be the oxygen sensors going bad and trying to correct a problem that isn't there?

[tonythetiger]

Hope this is some help even though it is an uneducated guess, but easy enough to check.
I would look to the fuel pump relay...you can feel if it is getting hot, plus you can jump it out (its right next to your foot) and you could have a failing fuel pump as well. You can hear a failing fuel pump sometimes.
Check for leaks on the replaced AOS, I had the issue with mine after AOS service and that was what was wrong. (I didn't get any codes on this, however)
I would think the oxygen sensors would send a code if they were failing, not sure. also, the o2 codes only indicate something is out of whack, doesn't mean "bad sensor"

[Sdav86]

When I first started having the codes pop up, I went ahead and replaced the aos. That solved it for a couple months then they came back so I replaced the maf. Same story. Ran fine for a couple months then the codes came back with another one saying that the idle rev was too high. I haven't heard any noise from the pump indicating that it's going out, but that doesn't mean anything. I've also had a fuel treatment done just in case the injectors were fouled up. The car only has 99k miles on it.

[thstone]

Please post the most recent codes...

[cas951]

Have you cleaned the throttle body? If not give this a try.

[Sdav86]

Originally Posted by cas951

Have you cleaned the throttle body? If not give this a try.

I have. I also took off the intake and cleaned it.

[Sdav86]

Originally Posted by thstone

Please post the most recent codes...

I'll have to do that after work. The batteries in my reader died and I have to get ones ones after I get off

[Sdav86]

Just a quick update. I replaced the oxygen sensors and it seemed to help, but now I have a new issue. The car is acting like it isn't getting enough gas when I take my foot off the gas peddle. As soon as I take it out of gear, the car shuts off as if I turned the key. No sputtering, just shuts off. When I turn the key again, it fires right up. I suspect either the fuel filter or fuel pressure regulator might be to blame. As always, your opinion is valued