P1155 & P0161
My AutoTap diagnostic software/hardware shows these errors as:
P0161 Heated Oxygen Sensor Heater Circuit (bank 2, sensor 2)
P1155 Alternative Fuel Control Module Has Activated the MIL
I cleared the codes, but almost instantly the P1155 returned. The description provided by AutoTap does not indicate which sensor is the culprit, however, in another thread here, P1155 is defined as:
P1155 A/F Sensor Heater Circuit Malfunction (Bank #2 Sensor #1)
This question must have been asked a million times, and I simply can't find the answer... but which sensor is B2, S1? And, when I order generic parts, how do I make sure that I grab the right one? According to some technical papers I've found, an A/F sensor is quite different from a regular O2 sensor - it apparently has a much wider range... so, going to a parts store, what do I ask for?
I have found four sensors and their connection points (two on each side of the exhaust manifold). I've disconnected them one at a time, cleaned the terminals, and reconnected them. There are four terminals on each plug. Two seem to be for resistance, the other two for voltage. One of them reads all over the place on with resistance (tested with engine running, sensor unplugged from harness, and testing directly at the sensor connector terminal).
I have an extended warranty for this Rav4 (2002, 2wd, Florida, 50k miles) through Warranty Gold - who has, of course, gone out of business after taking my $1200 premium. Oh well...