Why does the F 150 whistle at highway speed in the cold?
Year : 2006Make : FordModel: F150Engine: 5.4
Thanks for visiting Ja.comA bad cat converter can cause a whistle like this. Check the exhaust backpressure first looking for no more than 1 PSI at 3000 RPM in neutral. If the backpressure is high, address as needed and recheck operation. 2. If the exhaust backpressure is OK, monitor the VCTADVERR (Variable Camshaft Timing Advance Error) for bank 1 and bank 2 while driving. The reading should stay around 0* at all times. If the reading is going abnormally high on either bank, address the variable camshaft timing problem and recheck operation.
ASE Certified Service manager of Firestone