Quote:
Originally Posted by dpaul
...I do find it a little suspicious that you had all four sensors give errors at the same time. It's unusual for all to fail at the same time. [As I understand those four codes, they relate to LACK of Voltage (open circuit) in the O2 Sensor HEATER circuit which is separate from the O2 Sensor SIGNAL circuit, and as you confirm below, all FOUR of the Heaters are powered by F38 on his model, on the SAME circuit.] It might be that they failed sequentially over time, reflecting an abysmal lack of attention from the previous owner but could also reflect a common electrical issue. All four sensor heaters receive a common B+ (through fuse F38 or maybe F04, the latter in the DME box in engine compartment), shared as George pointed out with the breather heater; could be a problem in that wiring.
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I was NOT suggesting that the Breather Heater directly caused a "restriction" in the PCV Vent to Intake. I was suggesting that heater is on the SAME F38 circuit as the four O2 Sensor HEATERS that show fault codes, presumably for "open circuit" in that heater circuit. That's why I suggested checking F38 and asked if recall had been performed.
Gary states he has only had car for a year. He does NOT state when the Fault Codes or Smoking at WOT first occurred, or if they were present at the time of purchase. He states he replaced BOTH Pre-cat O2 Sensors (NOT sure why ;-), and YET he has same O2 Sensor HEATER codes for Pre-cat Sensors. I don't see any indication for replacing Post-cat sensors for same HEATER circuit codes. If there is some reason that Post-cat O2 Sensors could cause "Smoking" @ WOT, please enlighten me.
Let's see what Gary finds by testing F38 fuse & circuit, and seeing if HEATER codes return. Also what he reports as far as Breather Heater Recall and oil in Crankcase Vent to Intake hoses. I trust you agree THOSE are logical tests & examinations to conduct BEFORE replacing parts?
The ONLY thing I can definitively state from Gary's info provided thus far is that all 4 O2 Sensor heaters, and Crankcase Breather Heater are on same F38 circuit per TIS schematic AND he reports O2 Sensor Heater circuit faults.
That raises the likelihood of Breather Heater restriction (possibly during colder weather over the winter) from lack of proper function of that heater due to short which blew F38. So I'm basically agreeing with your observations, but putting a little more emphasis on the Breather hose restriction causing smoking, causing "misfire", etc. -- JUST a theory at this point, pending MORE INFO.
Thanks,
George