BMW, 740il, 1996, 104,000 miles, 4.4 L
I changed all 4 oxygen sensors due to mileage No DTC prior to new O2 sensors. Purchased SNG sensors sn4-204 "after" and sn4-216 "before". As soon as I installed the new sensors I got DTC P0135 and P0155 ( both "before"- O2 sensor heater circuit malfunction)
When I reinstalled the old sensors the DTC cleared. So I returned the SNG sensors "before" and bought 2 Bosch 13-559
I kept the new SNG "after" installed
As soon as I installed the new "before" sensors the old DTCs disappeared but two new DTCs appeared P1186 and P1187 (Manufacturer Contrl Fuel Air Metering)
The website claimed SNG sensors are superior and made in the USA. I believed it at the time.
Could it be the new "after" SNG sensors are bad too?
What would cause these codes and how do I fix it?
When I returned the "before" sensors the rep stated I might need to have the computer "flashed" but I haven''t a clue what that means.
*donation made* :D
Thanks in advance,
have the same problem?
Thursday, September 13th, 2007 AT 8:29 PM