So, my EM light came on a couple of weeks ago, plugged in my mates Delphi laptop. P1646 error, Bank 1 Upper, short or open circuit. That's the right hand side as you sit in the car, upper O2 sensor before the CAT. Went cheap online and got a sensor for half the price of a Denso sensor, it worked for 2 days then same error code. Grrrr! Plugged in the laptop and it was giving some real bogus readings totally different from Bank 2.
Today I bit the bullet and purchased a proper Denso 02 sensor, Q-E608 from Euro Car Spares as recommended. Hey presto all is now fine again, the moral of this story is don't mess about with cheap aftermarket O2 sensors, they may not work so good.


Anyway, I still have a few questions if there are any tech guys out there who can read the photos attached?
Ignition on photo, all readings are the same for both banks, so this looks encouraging, but Idle, 1500rpm & 2400rpm has some differences so;-


1. Are these readings OK?
2. Should I have purchased 2 new upper sensors to balance it better?
2. Or do I have other tuning issues that need addressing as the readings are a bit unbalanced by the look of this?


This is getting on for a 2 year love affair, I have loads of other issues to sort before this car is spot on, so any help on this one would be greatly appreciated as these cars are just so beautiful.


Cheers Pete

 

When I did my car I changed both O2’s just so I do not need to be concerned. However, after changing the purge valve my O2 readings came in line with what I was looking for. Just food for thought! I should mention I did not have a code for the purge valve.

 

PeterG: what I want to know is how did you get to the O2 sensor? I looked at both banks today and was wonder how I would ever be able to change them.


LannyL81

 

What year car?

Gus
Www.jagrepair.com

 

the uppers are doable but you will need to buy the sockets made for removing these sensors. I replaced my drivers side upper, it was tight but got it out. I was lucky that my car is rust free and not rusty parts on the motor so it came out pretty easy, not seized up.

 

I got the ones on my 99 from the top but I understand the 06 has other options. The one on the right was easy to get to but the one on the left you need to remove the coolant tank.

 

on my 03 I got my drivers side upper out and back in with out removing the coolant tank. It was tight and I cussed a lot but I guess my woman like hands helped, ha ha ha.

 

Hi Lanny,
On right hand side, remove your intake pipe one jubilee clip to air box and 2 bolts on top of the throttle body, easy job that one, then fish around the wires and pipes the upper sensor is the grey plug. Mine came off easy enough as I had 2 new CATs this summer so not seized in, got it with a ring spanner plus wrench on the end after cutting off the plug to get the ring spanner on. The upper right is by far the easiest one to get out. The lower ones require a ramp, but not too hard to get at.
Not done the left side yet but I would remove the header tank myself, that's also easy enough, done that recently to replace the missing magnet in my float. Tricky job that one like surgery sticking in 5 x 2mm dia x 4mm long magnets and sealing them into the float. But that job saved me £100.00 plus, and it works too.

 

Blimey don't know how you did that? I defo would have to remove the header tank to get to that one, more stuff that side too.

 

It's a 2000 XKR 4.0L, can you make sense of those reading?


Also what's the purge valve all about how do you know if that needs changing? And does that effect these readings?


It's a school day every day with this car, but worth it! lol.

 

Well you have a XKR so your access may be blocked more then on my normal XK8

 

I am attaching a few links from my page on Reading and understanding O2 readings for you to read.

Link JagRepair.com - Jaguar Repair Information Resource

Link JagRepair.com - Jaguar Repair Information Resource

I am also going to attach a few photos on the R&R of the O2’s. I used an open end wrench on both sides the one under the coolant tank was a little harder to get to but I used a box end wrench attached to the open wrench to give me leverage.

I hope this helps..

 

Hi Gus,
After helping my mate with his XJ6, he tried to use cheap O2 sensors also, which did not work and now reading loads more about the subject I reckon you are right, you need to replace both Upper O2 Sensors with proper Denso ones, as slightly different resistances from these O2 sensors feeding back to the ECM give you a slightly different mixture on one bank or the other, going to change my header tank side also, once I have completed my suspension restoration & lowering project, which has took my car off the road for the time being. Will post a few picts of that shortly.