I installed 4 new O2 sensors and a new cat downpipe and I am still getting a CEL and code P0158.

Ideas?

 

Dont you need o2 sensor orientation when installing new o2 sensor?

 

I only thought that was required if they were somehow plugged in wrong.

 

My first check would be to confirm the signal ground at the connector for the sensor and if not present, check it at the ECU.

If the ground is missing at the connector, you can just ground the pin with a jump wire to see if that clears the fault before actually fixing it properly.

 

I will give that a shot.

Is there a definitive answer regarding the O2 sensors needing "orientation" if all 4 were replaced at once with new downpipe/cats?

 

My understanding is that was only needed if something got mixed up when unplugging/replugging sensors. Assuming you replaced them one at a time to ensure nothing got mixed up, you should not need a reorientation.

 

+1 on what Vee said.

 

I have no idea if they are plugged in correctly as a local exhaust shop replaced the sensors when they replaced the downpipe/cats.

Can anyone help me with the proper orientation based on the factory wiring colors?

The two sensors that are pre cats are plugged into the connectors on the passenger's front fender. The connector with the unique BROWN wire to the sensor for cylinders #1, #2 and #3 and the connector with the unique GREEN wire to the sensor going to cylinders #4, #5, and #6.

The two sensors that are after the cats are plugged into two connectors right behind the valve cover. The connector with the unique RED wire to the sensor for cylinders #1, #2 and #3 and the connector with the unique BLUE wire to the sensor for cylinders #4, #5 and #6.

 

Oops

 

On the AJ16 engine the #1 cylinder is the forward most position ( opposite of the AJ6 ? ) . So the B1S1 ( bank 1 sensor 1 ) is on that pipe forward of the forward Cat . On the ECU side of the connectors they have the same wire colors with exception of the one important return signal wire to the ECU . B1S1 Green , B2S1 Brown , B1S2 Blue , B2S2 Red . Best to follow with hands and eyes to the installed pipe position . Look for some corrosion of the B1S2 and B2S2 connectors behind the back of the valve cover .

Ref wire diagram .

 

My previous advice was

My first check would be to confirm the signal ground at the connector for the sensor and if not present, check it at the ECU.

If the ground is missing at the connector, you can just ground the pin with a jump wire to see if that clears the fault before actually fixing it properly.



So what was the result of that test?

 

I replaced new cats and 4 new 02 sensors in my 1995 XJR I found no new orientation was required, but I marked every wire to make sure.
Snowball

 

Orientation is not a physical thing, theyre talking about using pdu(we havent had a funstioning one in years and sdd no longer supports that function from jaguar. I know cause i still have a 95 and 96. We always did a orientation regardless. It was the early days of ecu adaptations. Is it always needed to, but more often than not. It runs different injector pulse widths on certain cylinders and looks at the 02 readings for what should be seen and what is seen accordingly. Then adjust for best operation. Matter of fact i always did 02 orientation, throttle idle speed setup and trans kickdown setups all at the same time. Try to find a jagguar specialty shop that still has the capabilty to run this on older cars. Jaguar manufacture does not care about old cars and the needed time and space in programs to maintain these diagnositic tools at dealer level so theyre eliminated. Only dealers and techs that kept and maintained this dinosaur equipment. Thick about brick phone vs todays smart phones

 

I do have a specialty shop close to where I work that works on a lot of older German and British vehicles (Robinson Auto in Springfield, MA) I will give them a call and see if they still offer this service.

On a good note, all 4 sensors were plugged in where they were supposed to be. I unplugged them, gave them all a good cleaning and a dab of dialectic grease before putting everything back together. Cleared my CEL with a simple OBDII reader and no CEL on a 100 mile trip to the airport this morning.

Time will tell if the CEL remains off.

 

Another 100 miles and the CEL has remained off.

Fingers crossed.

 

use your reader to see if the "readiness monitor" for cats/02 sensor and run and is ready. It can be a hard one to get to run. But if it is ready then it didnt see a fault again

 

I spoke too soon. This is becoming very annoying. CEL light came back on. I may be at the point where I have a professional look at the car.

 

http://www.jagrepair.com/images/Trai...20-%202000.pdf

See page 61 or page 113 of 360

I have some other items to check in the morning