Howdy.

I had p1646 show up on my 2003 STR. The reader (CReader 6 plus) asked for the make of my car and reported the fault as fuel pump relay #2. After reading up on these boards I am thinking upstream O2 sensor, passenger side. I was going to change the oil tomorrow and I think this is the sensor right next to the oil filter so that works out.

Is there anything else I should check before ordering a new o2 sensor? Maybe take it out and brush it off or switch it out with the other upstream? Where is the other upstream located?

I also have the data from the reader: (I omitted some stuff like fuel trims, temps, air flow, timing, and pressures)

O2 sensor output voltage B1-S2 ---- 0.805V
O2 sensor output voltage B2-S2 ---- 0.805V

equivalence ratio (lambda) b1-s1 ---- 0.999
O2 sensor current b1-s1 ---- 0.00mA
equivalence ratio (lambda) b2-s1 ---- 0.999
O2 sensor current b2-s1 ---- (-0.20mA)

O2 Sensor
Bank 1 Sensor 1 ---- no data

Bank 1 Sensor 2 ----
low sensor voltage ---- test value: 0.050, min: 0.000, max:1.275, status: pass
high sensor voltage ---- test value: 0.950, min: 0.000, max:1.275, status: pass
min sensor voltage ---- test value: 0.070, min: 0.000, max:1.275, status: pass
max sensor voltage---- test value: 0.075, min: 0.000, max:1.275, status: pass

Bank 2 Sensor 1 ---- no data
Bank 2 Sensor 2 ---- no data

 

other upstream is located pretty much at the same place, opposite side of the car.

Don't brush it off. Don't clean it. Replace it. It's decently cheap enough (60-80 bucks), and it literally takes 5-10 min to replace it including taking off the bottom cover.

A month ago, I replaced mine in my 2003 STR. EZ PZ. Here are my recommendations.

1) Factory Denso sensor. You can find this one on Amazon and it ships prime.
2) O2 sensor tool. This is the one I have:
3) PB blaster. I sprayed some on my old O2 sensor before taking it off. It came off like butter.

Good luck!

 

CReader is wrong. JTIS / codes PDF is right

Search on here should show what others did...

 

Also David, I noticed you're in San Diego. If you need, I can roll down to you and do the work for you free of charge. Just let me know, I'm in the Inland Empire.

 

Also, check your fuses first lol.

 

Thank you very much for the offer but that is a ways to drive and I need to start becoming more familiar with this car. Lets just hope I don't break something along the way (maybe a plastic fastener or two would be ok).

I was having issues downloading the JTIS. Does anyone know the fuse for the o2 sensor?

I found the 2003 electrical guide and saw that the heated o2 sensor relay was marked R2. are there any smaller fuses I should check?

 

One last thing I forgot to mention. I added a full can of Techron during this last fillup. The MIL came on when I had about 1/2 tank gas. Has anyone heard of techron setting off the o2 sensors? I will fill up (currently at 1/4 tank), erase the code and report back.


Update:After filling up I cleared the codes and noticed that all of the fuel trims are set to 0.0 %. any thoughts?

 

The techron shouldn't have set off the sensors.

At startup, the o2 sensors do not read. They have to warm up first. Takes a couple of seconds to a minute.

 

There are some things that will poison an O2 sensor. Silicates (anti-freeze) and some sealants (silicone) will render O2 sensors inoperative. Oil additives or shock (both physical and thermal) or heater damage can as well.

Denso's are cheap at Walmart. $80's for upstream, $40's for downstreams. Replace all 4 for around $250

 

Here is what I did on my 2005 STR.

https://www.jaguarforums.com/forum/s...6-p1647-86397/
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O2 sensor replaced and oil changed. No more codes. Mods please mark this as resolved. Although I do have a new rattle under acceleration after the car has warmed up (no noise at idle or when revving in neutral). I will double check the heat shields and re-tighten the O2 sensor.

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