Here is the latest.......
Renault have had the car for 3 weeks. Having changed oxygen sensor, temp sensor and HT leads the fuel injection ECU was giving the same "oxygen sensor" fault everytime. They eventually came across what appears to be the underlying fault - the connector between the engine wiring harness and the ECU was corroded.
They attempted to get it working by cleaning up the pins as best they could but without success.
I then heard from the garage that to get the car working would require a new ECU and wiring harness, the parts would take two weeks to get hold of and that the job would cost the best part of £2000.
I replied by saying that I would live with the fault for now.
We collected the car thismorning and to our surprise, it's working perfectly - no sign of any misfire and no warning lights coming on. I can only presume that when they fitted everything back together for the final time the pins must have made good contact.
This leads me on to my next quest for info. I don't really want to leave the connector as it is as I'm sure it's only a matter of time until the fault returns.
Firstly I want to have a look at cleaning the contacts myself - I don't mind spending all day cleaning them if it saves me £2000... Apart from disconnecting the battery first, is there any precautions I should take when removing / disconnecting the ECU?
Secondly I was going to look into replacing the actual connector on the loom. Do you know if it's a 35 of 55 pin connector? I've a quick bit of looking on the web and have come up with this as a possible candidate for the socket (if it's a 55-way connector)http://catalog.tycoelectronics.com/TE/bin/TE.Connect?C=1&M=BYPN&PID=169674&PN=963534-1#features
Finally if the ECU pins look bad, is there any chance of changing the connector or is the ECU totally sealed.? I was thinking of getting an ECU off eBay (Bosch Motronics for about £10) and attempting to swap out the PCB mounted connector. I know it would be a difficult job and that you would have to take ESD precautions but I'm bit of a dab hand with the old soldering iron.
Any input from you guys would be very much appreciated..
I must admit it was great getting back in and driving her today - that V6 is sooo sweet.
Oh yeah..is there a special king of grease for putting on contacts to stop this happening again??