Hello fellow Roverites,
Winston is an 04 D2 with 166k.
This is in the realm of Car Talk's "Stump the chumps segment". Every since I replaced my power steering pump, I have been tossing the classic P1171 & P1174 codes, meaning an air leak. It was not happening before so I know something is not fitting right. So in trying to track that down, I disassembled the hoses from the air box to intake, resetting them and clamping them down. All of a sudden the car started popping the P0134/5 codes. Here is the thing: in watching the ultra gauge, I see voltage going thru the O2 sensors. I cleaned the MAF with cleaner, cleaned the plug contact with electronic cleaner. It still pops up. After I clear it twice from the ultra gauge is does not return, but will return the next morning when I start it again totally cold.
Any thoughts?

 

Well maybe there is a leak somewhere else, like intake mani gasket, or IACV, or boost vacc line........

 

Have you checked your wires and plugs? I had a similar issue, and when I changed my plugs and wires (they were *long* overdue) I didn't have the issue anymore. I did happen to order new Walker 02's anyway, but have not gotten around to installing them.