hi ,had problem with front lambda sensor (this is update to previous post),i had sensor replaced.2 days later went on motorway journey travelling at average 70mph and all was fine,returned to car after about 5 hours and whilst travelling around town at 20-30mph engine management light reappeared,i put the code reader on and got the same code saying fault with sensor(car running fine)i deleted code and carried on with journey and light never reappeared until about 7 days later when doing a similar trip.no problem at speed but light appears when have slowed to 30ish mph after a good drive at 70-80mph.the same day i deleted code but next morning shortly after pulling away light reappeared.i deleted code yet again and it didn't reappear all day(yesterday)question is does the car need the proverbial italian tune up to clear cack which might be causing problem or would there be something else causing problem.car seems to be running well.any input would be greatly appreciated,thanks

car is 1.2 classic estate azq engine and code fault read front sensor at fault which got replaced,have also had rear sensor replaced in past

Edited 15 August, 20169 yr by captainklutz

Where did you get the replacement sensor from, and what part number was it?

took car to local garage who I've used for years and never had problems with so i don't know part number I'm afraid or where they got it from sorry.

Edited 15 August, 20169 yr by captainklutz

They might have used a rubbish part.

Needs some runs with VCDS logging the relevant groups (030, 033, 041) of live data really.  Where are you located, approx.?

Edited 15 August, 20169 yr by Wino

im in the black country,west mids.what exactly are those number groups and can they only be found using vcds, i have a code reader but i think it just gives me the code 

Edited 15 August, 20169 yr by captainklutz

Yup, VCDS.  If you were closer I'd happily have a look for you, know anyone near you with VCDS?

It would be a start to know what the code is.

Edited 15 August, 20169 yr by Tech1e

no don't know anybody but thanks for the offer,you're a gent

code was coming up as 16514-o2 sensor circuit-malfunction(bank1 sensor 1)

Edited 15 August, 20169 yr by captainklutz

Did you ask the garage to fix the problem, or just change the sensor?

If it was the former, take it back. If the latter, they shouldn't mind telling you where they bought the replacement, if you know them.

 

I'm a bit suspicious of the wiring loom in the vicinity of the plug/socket, mainly because other connections in that area are rather prone to failure. It's possible that one of the skinny little wires running to the ECU is almost, but not quite busted, so the sensor is sometimes losing it's supply temporarily.

 

The orange-ringed area is where I'm thinking of:

 

thanks for the info much appreciated,will try to have a look or get mechanic to.cheers