Lambda probe

[dubster]

Anyone else had this problem. Put my 172 in for a service as it wasnt running as well as I thought it should do. Got it rolling roaded and was only putting out 166bhp, has a superchip and induction kit, was well shocked. It was taken to the local Renault dealer and they diagnosed a fault in the lambda probe. New probe put it, then rolling roaded at 184bhp!! why would a probe affect this?? Anyone else had this.

 

[qwerty]

Have you still got the cat in place?

Does the 172 have 2 lambda probes like the 182?

If so which probe was faulty?

I suspect the pre-cat (1st) probe as thats the main one. If faulty then the fueling could be all wrong and, either way, you may have damaged the cat. Check it out at an MOT centre so you dont get a sudden shock come MOT time!

 

[edde]

The normal ECU programming used the lambeda sensor below 4k above 4k is runs a fixed fueling program. Therefore a faults lambeda wouldnt be noticed above 4k.

However the superchip remap might change the rpm the sensor is used for in fueling.

 

[dubster]

Only 1 probe as far as i know will find out more tomorrow when i pick the car up and have left the cat in place, will take your advice and get it checked out by my pal he is an mot tester, take it to him.

Eddie it did seem to die around about 4k before the service apparently it running perfectly now

 

[edde]

Quote: Originally posted by dubster on 25 August 2004

Only 1 probe as far as i know will find out more tomorrow when i pick the car up and have left the cat in place, will take your advice and get it checked out by my pal he is an mot tester, take it to him.
Eddie it did seem to die around about 4k before the service apparently it running perfectly now

The mk1 has one 1 sensor precat the mk2 needs one after it to deal with emmisions laws.

I wouldnt worry about it failing the mot so long as the car isnt reved over 4k and I dont think it is then the lambeda sensor will fix the fueling and ensure the engine runs fine.

Mike on here has a 172 with loads of mods decat and stock fueling and his car would still pass the emmisions part of the mot as the ECU compensates for the restriction removal (ie decat head work etc) in his car.

 

[markh]

Some later model MK1s have dual senors... one before and one after the cat