This is for a Northeast 98 Vulcan with the wonderful secondary AIR system normally shoehorned only into California cars, but as I understand it, was fitted to certain NE cars.
I'm once again getting a P0411 code ("the flow in the secondary air injection system is incorrect") on hot idle.
Relevant diagnostics words from the Ford Manual:
"The functional check may be done in two parts: at startup when the AIR pump is normally commanded on, or during a hot idle if the startup test was not able to be performed. The flow test relies upon the HO2S
to detect the presence of additional air in the exhaust when introduced by the Secondary Air Injection system.
associated with this test is DTC
Air flows into the manifold on cold startup so the pump and valve seem to be OK.
The code appears after driving about 20-30 minutes while idling at a traffic light or stop sign -- gotta be the "hot idle" referenced in the manual.
My question is what or where is the "H02S" ?
(I've done a search, but everyone here who uses this acronym apparently knows what it is...)