Technical Lambda Sensor problem

[Seamus2012]

On Mutliecuscan I am getting "Lambda sensor above catalyst failed" or similar. Is this the O2 sensor. If so I have recently replaced this.

The symptoms are that the engine will start stuttering after about a mile on an uphill section. Will start again then fail.

Any advice please.

 

[dac69er]

Did you fit a cheap sensor?

If the sensor is ok. Then have you checked over the wiring?

 

[rallycinq]

Which car and which engine?

D

 

[Eklipze3k]

2002 Seicento 1.1, according to previous thread.

Am I right in thinking that the MPI has 2 lambda sensors - one pre cat and one post cat?

 

[Seamus2012]

Did you fit a cheap sensor?

If the sensor is ok. Then have you checked over the wiring?

Yes, cheap sensor. Wiring looks ok. I have put the Multiscan on and it is showing "Open Loop", so presumably it is faulty or wiring fault. I did run ok initially

Not sure what other checks can be run on it.

 

[Seamus2012]

Which car and which engine?

D

Seicento 1100, year 2002

 

[rallycinq]

Yup, 2 sensors, has the OP changed the right one and are the colours correctly matched, see the 'Free Cinq' thread....lol

D

 

[Seamus2012]

Yup, 2 sensors, has the OP changed the right one and are the colours correctly matched, see the 'Free Cinq' thread....lol

D

I changed the one that is under the ally heat shield.

The sensor was prewired so assume that is correct.

 

[rallycinq]

I changed the one that is under the ally heat shield.

The sensor was prewired so assume that is correct.

never assume

D

 

[Seamus2012]

My saga continues.

I have replaced the faulty sensor and M,ecuscanner is now showing voltages for it. However the engine management light is flashing when the engine is running. The scanner is not showing any errors to clear, so I don't know where to look now.

Any ideas please.

 

[rallycinq]

Check the timing hasn't jumped.

D

 

[Seamus2012]

I have been going through it again today. Replaced the top O2 lambda. But still getting the same problem.

I had the EML flashing so ran the Phonic wheel in MES and the flashing has now stopped.

It will run until it gets hot, then it might stall at idle, or if driven it will stall under load. Need to wait then for around 30 secs before it will restart and then it will only be for a short while.

When running it smells rich, but it also sounds like fuel starvation which is contrary to the former.

I am enclosing some readings from MES to see if anything jumps at anyone.

Hope someone can help me get to the bottom of this.

Edit
Just looking at the readings, could it be the bottom lambda at fault.

 

[Seamus2012]

Anyone any ideas on this please.

I have just tried running with the bottom one disconnected and then the top also. Both presented the same symptoms. Can't make up my mind whether the O2 sensor is faulty or whether it is elsewhere.