Hi everyone.

While I am working on fixing all issues with my 2003 XKR project, need your support on the below. I have no check engine light (NO CEL) but when I try to read the short or long fuel trims, I get nothing. Checked codes and I have P0037, P0057, P1646, and P1647. Tried clearing codes and doing a reset, but they just come back.

While driving, the Upstream sensors ratio stays at 1%. Downstream reads around 0.7v with very little variation. I am using Foxwell NT510 Elite with JLR jaguar program.

I disconnected the connection harness just behind the throttle body to test each sensor. All 4 sensors heater circuit (two black lines) have continuity and the upstream ones are both reading 1.2 ohms. While I was there I also found the egr exhaust pipe linking to exhaust is broken.

The codes have been there even before I replaced and fixed the below:
- New Denso IFR5N10 spark plugs. Old ones had wrong part number

- New coils . Old ones where rusty, and had two wrong coils.

- New Denso 1976040 MAF, old one has wrong part number.

- Fixed air leaks on intake tube.

- New exhaust after cats to tail pipe. Previous owner fitted some cheap resonators with restrictive small diameter pipes and deleted cats inners although kept the cover. No idea why would anyone do that.

Therefore the question is, why are all sensors having fault code and no check engine light.

In the meantime, I am going to fix the egr exhaust pipe.

Thanks.

 

If someone has taken the guts out of the catalytic converters then the sensors will not work right. I assume you have no emission test in Jordan

 

Hi Pistnbroke,

Yes unfortunately emissions is of no issue here. Cat delete should only affect the downstream sensors, but I have upstream codes as well. I will get the cat sorted later in the project though.

I am worried that all O2 sensors fault has a totally different issue.

 

Maybe a misleading OBD tool - just possibly you have pending codes. They would not put the MIL on.

If you're forever OBD clearing, the codes can't turn from pending to actual.

And/or, is the MIL broken or faked in some way?

 

How does it drive and what is the fuel consumption?

 

Thanks guys. i just fixed the broken EGR exhaust pipe.

Prior to changing all the above mentioned parts, its was barely running, missing, extremely rich, smelled like exhaust in the cabin, black fumes, even raw fuel from exhaust.

Now it purrs like a Jag. I think I will need to drive it more to check the fuel economy. It says average 16litres/100km but I dont trust it. Still has some other issues including transmission not feeling 100% ok although no code, and needs a full front and rear suspension refresh.

I just did a recheck and you are right, the 4 O2 sensors are pending. Not sure how long will this take. Will pending O2 cause unreadable /null short and long term trims.

Thanks

 

two are for the heaters

it’s not going to trim with no signal from the widebands.


to the wiring diagram you go

 

Wrong spark plugs, wrong coils, wrong MAF. So why not wrong o2 sensors?
Buy the correct Denso o2 sensors and check that you have 12v for the heating.

 

Hi guys

i got two upstream O2 sensors Denso 234-9029. Installed one one bank 2 and the code disappeared. Will do the same for the others.

The sensor that was on the car was 9f472ab denso 3110. I dont know if this was a correct one.

I will update you once I install the others.



Tomorrow I am dropping the transmission as I am having a leak next to the torque converter, hard shifts and sometime get gear box fault P0784. Fingers crossed that it will only require new fluid. Will put in Mecron SP as suggested in this great forum.

 

If you drop your ZF pan, be sure to replace the Mechatronic sleeve before you replace the pan. The factory sleeves are prone to leaking as the years go by whereas the new-and-improved sleeves do not leak. That sleeve may be the source of your ATF leak....

 

Yes I will sure do replace that and the other 4 rubber tubes and do the zf procedure on refilling. Reason to drop the transmission is because the leak is between the torque converter and engine, most probably the seal as when looking in the hole at torque converter its totally dry. Picture is example of what I think might be the leak issue.

 

You will be very happy with Mercon SP ATF as long as you indeed have the ZF 6HP26 transmission....

Good luck and keep us posted....

 

I'd say double/triple check the mechatronic sleeve first. This is where the electrical connector goes into the transmission (rear, by the output shaft). Clean the area very well (brake cleaner), drive around, and check again. Fluids have a way of travelling with gravity and air flow sometimes making it difficult to locate the true origin. That seal fails quite regularly. The "catch" is that, in order to remove the plastic sleeve, it needs to be unlocked from the bottom of the transmission, with the pan off (and fluid drained). This is, of course, a MUCH easier job than separating the transmission from the engine.

Another area to check is the 2 cooling lines to the cold side of the radiator. They are normally pretty robust, but anything can happen on an aging car.

Best of luck, keep us posted.

 

Thank you for the great support. Here are some pictures. Do you see the problem

 

Going back to the initial discussion, is .7v (no variance) on the downstream O2 sensor ok? Have the same.

 

Hi CA,

I have not replaced the downstream yet but also getting 0.7v constant. Not sure if it is working. Will wait and see and will replace accordingly.