O2 sensor issues

[Mogilyboy]

Hi can anyone offer any advice?
I have a 1.8 20v t leon, which recently failed its MOT on emissions.
So got a mate to plug it in and it gave a code 16514.
So I've replaced the Cat and the first o2 sensor and cleared the codes. Got it through the MOT, but the code has come back, does anybody have any ideas what else I can check?
Cheers

 

[mty12345]

Hi mate, ross-tech.com is the best place to enter the codes for more info. http://wiki.ross-tech.com/wiki/index.php/16514/P0130/000304

That one comes back as a fault in the heater part of the front 02 sensor. If you've had the same code on 2 sensors then i would definitely suspect the wiring going to it. These cars are getting on now and the wiring for the O2 sensors is in an especially harsh enviroment with the heat from the exhaust.

 

[Mogilyboy]

cheers, i will have to have a rummage around

 

[RUM4MO]

Also maybe check if that supply has its own fuse, it is always best to replace the pre-cat Lambda sensor when you replace the cat. I just hope that you have fitted a good quality Lambda probe, ie NTK like the original probably was?