Piggybacking off what HeyYou said, "inc" means incomplete, which means the computer hasn't run the test yet. The PCM on any vehicle will almost never run the oxygen sensor monitor while the car is idling, it has to be driven. It does NOT mean that the sensor is bad. If you have a live data function on your scan tool, look up the parameters for 'B1S1' or maybe 'B2S1' It should fluctuate between .2 volts and .8 volts, roughly, but only after the vehicle has entered closed loop (may be listed as 'CL' on your scan tool). You have to let the car run for a bit for it to enter closed loop, it is directly related to engine coolant temperature. If you wish to test the sensor, pull off a small vacuum hose. O2 should drop to approximately .2 volts (lean) then pick back up closer to .8 volts (rich)as PCM dumps more fuel in to compensate for lean condition (of having vacuum line removed). If it does this, the oxygen sensor is working properly, and replacing it is pissing away more money.

 

Counterpoint.

As they age, O2 sensors get slow. If you don't replace them on a schedule, you can **** gas out your tail pipe due to them being slow. Or risk preignition due to running too lean.

That's like "As long as the air isn't showing, the tires are good!" But as they wear down, they'll usually take longer and longer to stop; that's why there's tread wear bars, and that's why you SHOULD replace them BEFORE they go bald.

RwP

 

You are right, they can get slow and a little lazy. Maybe worse fuel economy, but I've never seen a car in the shop detonating from a bad O2 sensor in 15 years.

But if you suspect it is slow and lazy, you can graph it, which is probably more than the scan tool she is using can handle. But replacing an O2 sensor just because the monitor is not set,on ANY car, after having the battery disconnected (which wipes all the monitors), and not having driven it is a waste of money. You can stick a brand new O2 sensor in, and the monitor WILL NOT run, idling in a driveway, 95% of the time (the o2 heater monitor WILL run, if it has one).

Considering she's got a p1391, which is either a crank OR a cam sensor, she's going to have to replace one or both of those (since she obviously does not have an oscilloscope to look at the voltage pattern). And she's complained about cost, so one or both of those is going to do a job on her wallet by themselves. Not to mention an O2 sensor, which it sounds highly doubtful that she needs. And if she tries to change the o2 sensor for no reason and rips the threads out of the bung, or the entire bung out, then she's really going to be complaining about money.

 

Any tricks to getting the O2 out of a 2.5? Mine seems to be glued in

 

I'm guessing you don't have access to oxy-acetylene torch. When I'm at home and can't get something to the shop, I use MAP gas. You can get it at Lowes, usually in a yellow bottle, as opposed to blue bottles for propane. You just have to be very patient with it, you're going to have to heat it up for a while. I assume you know, heat the bung section of the exhaust pipe, not the sensor itself.

 

I will try that thanks.

 

Either that, or chemicals, a wrench, (pipe) and a big hammer.

 

Yea the pcm has to see the 02 sensors in running mode a certain amount of time to be "ready"..an complete.After battery is disconnected or a reset it has to go thru many start,run drive ,cycles.
That's a key factor ,after repair, to checking before a test if your required to get it [emmisions]..
On my Elm tester theres a 02 ready monitor section I go by.