Where do I find bank 1, sensor 1 on 2000 4.0 v8? Just got the code today but not sure where to look. Thank you.

 

Start with the workshop manual / codes PDF. Both are free downloads on here.

One or both may also be on JagRepair.com - Jaguar Repair Information Resource

They give the meaning and all the known causes plus specific tests to carry out. These will include wiring as well as changing the sensor if it's faulty.

 

Thank you. Went to Jag Repair and looked up code and the first line of possible cause was "misfire". Have had random misfire for some time now and when daughter mentioned the check engine light was on I was delighted and ran out and bought a new plug coil. Waiting for a code to tell me which one. Not happy with the P0133 as I still do not know which plug coil! Turned light off and await misfire code.

 

Quite often there can be a misfire that doesn't set a DTC and turn on the MIL.

How many kilometres are on the vehicle? It may be wise to remove the coils and inspect them for oil fouling, which can cause a misfire. If there is oil fouling on the coils, the cam cover gasket and spark plug boss seals will need to be replaced. If the engine still has the original spark plugs, they should also be replaced.

 

Thank you. Car has 230000 km, in showroom condition. Plugs have about 50000 km on them, no oil fouling of coils. The misfire has happened twice before, first time it took almost a year for the code to show up, second time code showed up with first misfire. Has been randomly misfiring for several months but no code yet so I am reluctant to change out all 6 remaining original coils ($90 ea.). Patiently waiting for the code to tell me which coil is bad.

 

I thought that P0133 is an O2 sensor, not a coil pack?

 

Typically, the P0133 DTC is caused by an exhaust leak or poor electrical connection. I have also seen it show up with P0420, Catalyst Below Threshold (Bank 1).

 

As sure as the sun rises in the east, Mikey is right.

OBD codes for your year are here:

http://www.jagrepair.com/images/Auto...tos/P20000.PDF


The fault description:

"HO2 Sensor sense circuit slow response" on bank 1, upstream sensor.

As oxygen sensors age, their response time slows down. An oxygen sensor is a normal wear and tear item, just like spark plugs and brake pads. Unless you know that particular sensor is new, or nearly so, I'd replace it and see what happens. It's not worth going too deep with troubleshooting at first on something as simple as this.

Per RockAuto, a good name brand sensor will set you back $37 at most. If you want to replace it, get one with the correct connector plug. Stay away from the universal fit models that require splicing the wires.

Your car will have 4 oxygen sensors, two on each side. For each side, one is upstream, before the catalytic converter, and the other one is downstream after the cat. For P0133, you'd want to the upstream sensor on bank 1. I'm currently having a brain fart trying to remember if bank 1 is the US driver or passenger side.

If you don't want to gamble $37 on a sensor, you could try swapping them side to side and see if the fault follows. Access is probably pretty poor, though, so I'd be inclined to just replace it. And if one side is getting old and creaky, the other side probably isn't far behind.

Only replace the upstream sensors, though. Avoid the temptation to replace the two downstream sensors. The downstream sensors monitor the efficiency of the cats, and strange as it may seem, the computer is happier to see the slow switching you'll typically see with old sensors.

 

In initial research into how to fix, the first cause as listed in Jag repair.com was misfire. That is how the thread drifted. I erased the code and if it returns, will replace the O2 sensor but my bet is on my recurring misfire. Will know soon.

 

The code came back so it is time to replace both upstream sensors (no point just doing one). From what I can gather from the JTIS, this needs to be done from below? Can this be done without a hoist? Hard to tell from the diagram exactly where they are.

 

Before you spend money on oxygen sensors, check for exhaust leaks. I have seen several vehicles showing P0133 that were corrected with repairing small exhaust leaks.