Our Mk 1 Punto (85 16V) failed the MoT on emissions. As I have just replaced the head gasket and it is running well our conclusion is that it must be the lambda or the cat. I have a 75 sx for spares (none of which usually fit - so if anyone needs a part let me know) so I have swapped over the complete exhaust with cat - the cat is a different part number and it just as easy to fit the whole lot.

My questions relate to the lambda sensor. Is there any real difference between the lambda sensor fitted to the 85 compared with the 75 other than the length of the lead?

If I fit the one from the 75 should I leave the longer length lead intact or should I cut it to the same length as the original?

I don't mind paying the £70 for a new lambda sensor if I have to, but I would be happier "recycling" the one from the 75.

Cheers

David

Anyone?

don't know for sure but check the number of leads; some lambda's have a heating element (thus 4 with 2 grounds (black) plus one for power and one for sensor, you could check these with a voltmeter to make sure they are the same); lambda sensor failure common after HG failure due to contamination with water; if leads and plugs are identical its probably worth a go; don't cut the lead; it is possible to test sensor output also...

Try your local motor factors for a lambda tester. Cant remember how much they are but that will tell you if yours is OK or not.
Also didnt the tester give you a clue as to what the problem would be.