MAF problem?

[dvu70]

I have a 00 c2 w/45k miles and I'm getting codes P1128 & P1130. I had a local Northern VA Porsche specialized shop check it out for me. They didn't find any vacuum leaks and the 02 sensors had been replaced @44k. They tell me it's most likely the MAF. Is there any thing else they should have looked at or should I go ahead and get it replaced? http://www.autohausaz.com has a Bosch egas one for $210. Thanks

[1999Porsche911]

I would thoroughly check the intake tubes between the air filter housing and throttle body for leaks. These error codes are reported by the O2 sensors because they are trying to richen up the system becuase you are running too lean. It could be plugged fuel injectors, leaking air intake. It also could be a bad fuel pump or pressure, but that is less likely.

Your scanner would easily identify whether the problem was MAF related. The MAF reads the flow of air and the computer adjusts the amount of injected fuel based on this info. The O2 sensor adjusts the amount of fuel based on what it reads for Fuel/air ratio. The codes are telling you that the O2 sensor cannot adjust enough. So, either the MAF is way off on the air flow reading, or it is accurate, but more air is being introduced into the engine somewhere AFTER the MAF sensor.

Things to try include, clean the MAF with carb cleaner or alcohol and reinstall. Clean the throttle body with carb cleaner. Run a few tanks of gas with injector cleaner added. Check every intake connection for leakage.