156 2.0JTS Lambda Sensors

Hi

I have a bit of a techie question - I hope somebody here can help out ! I have a 2002 2.0JTS with just over 50K miles. The infamous Motor Control Fault light came on the other day. My local garage plugged me in, and it showed:

P0141/P1141 Heated Oxygen Sensor (HO2S) 2, bank 1, heater control - circuit malfunction

He called it a 'sluggish' sensor. You could see the readouts from the other sensors responding to throttle change, but this one stayed pretty much the same. We reset the code, but it came on again about 10 miles down the road.

Can anybody tell me which sensor this is - I understand there are 4 sensors - 2 before the cat., and 2 after ? Even better, where's a good place to get hold of one ?

Thanks.

Hi,

I have exactly the same problem with my 2.0JTS. I had an Alfa specialist look at it and he confirmed that both pre cat sensors are down. What I was hoping was that some one could suggest a 'reasonably priced' replacement. I've spent days looking around and cant' find one for under £60. Also I'm confused are the sensors 5 wire or 4. Depending who's web site you go on you will find some state thay are 5 and some 4. Anyway any offer of a good supplier would be appreciated.

Usually it is just the connectors that are the problem.
There is design "issue" in that the pins don't push fully home on the other side of the connector. If you trim the face of the socket side it allows the pin to reach further in.

There's only 3 lamda sensors on your car and that code refers to the one in the right hand side of the down pipe.

The easy way to find out which it is though is to unplug them with the diag on and when the faulty one goes off then you have it.

Any Bosch dealer can get you the correct one.

Originally Posted by Smaky

There's only 3 lamda sensors on your car.

Are you sure?
I thought the 2.0JTS had 4 Lambdas.

ePER lists 4 for the JTS.

I'll check, but I'm sure it's 3 Lamda.

i dont use universal lambdas. they have a habit of triggering engine managemnt faults because they have the wrong resistance. stick to oem.

Thanks for your responses.

I spoke with a couple of people who claim to know about these things, but even they seemed unsure how many there were. The CD Parts list indicates 4.

In the end, I wheeled it into our local garage, and had it fitted. Had a good run last w/e, and all seems OK.

OK, the definative answer from my perspective is that a 2003 2.0L JTS has 4 sensors. 2 pre cat which are 5 wire wide band Bosch LSU4 sensors and the 2 post cat are 4 wire standard sensors. The wide band sensors were £88 each which hurt. Bosch part number 0258007156, I fitted them last weekend and all is OK. Found best place to get them from is www.justlambda.com, who delivered in 24 hours. Only issue was that the front 5 wire sensors were hardwired into the car at the sensor plug, so ended up splicing the new sensors into the old sensor wire. This meant I could have saved about £20 per sensor if I'd know as I could have purchased a generic LSU4 rather than the specific part number for the applicaion (which has the correct plug and wire length).