05SilverA8

Was a very hot day today and when I started up car and drove a few hundred feet I had a check engine light on. Any idea what may cause this?

Address 01: Engine Labels: 077-910-560-BFM.lbl
Part No SW: 4E0 910 560 J HW: 4E0 907 560
Component: 4.2L V8/5V A 0010
Revision: -------- Serial number: AUX3Z0D7748837
Coding: 0007773
Shop #: WSC 02313 785 00200
VCID: 285413F79BCB605EF37-807D

4 Faults Found:
17538 - Fuel Trim; Bank 2 (Mult)
P1130 - 001 - System too Lean
16558 - Fuel Trim; Bank 2
P0174 - 001 - System Too Lean - MIL ON
17536 - Fuel Trim; Bank 1 (Mult)
P1128 - 001 - System too Lean
16555 - Fuel Trim; Bank 1
P0171 - 001 - System Too Lean - MIL ON
Readiness: 0000 0000

Reset codes and started engine and no codes (yet).

TSHong

My first guess would be some sort of vacuum leak.

mishar

Usually it is caused by a vacuum leak. If it fixed itself it must be some valve stuck for a moment.

05SilverA8

I did find the hose that goes from the bottom of the air cleaner housing to the secondary air injection pump completely disconnected. Fixed this and no further errors.

aTOMic

Give it time...

Did you have any work done - like an oil change - lately?
That hose disconnected should have caused the secondary air system to set a DTC.

(I'm just jealous because I have been trying to cure my lean (multiplicative) codes for a while now).

-Tom