Mk3 NC 2.0 sport management light delete

so I fitted a manifold removing the precat, and can’t get the management light to stay off it comes up with a pre lambda sensor fault code I’ve changed this and still the light comes on. Is there a way to just stop it coming on. I know my previous clio 197 they programmed the Ecu can this be done? I’m in East Sussex if anyone can help

thanks in advance 

Stock ecu on the MK3 can be programmed apparently but removing the precat lambda will never work as this sensor is always required.

Why did you remove the precat lambda as surely car not running properly, management light aside?

The precat lambda sensor will need to be refitted, so I think you will have to fit a lambda boss and extend the original lambda wiring.

Quite a number of previous posts on this as first cat delete /replacement with performance manifold adds quite a chunk of horsepower.    

Sorry maybe I didn’t word it well I still have the pre and post cat lambda fitted I replaced the precat lambda with another one but still get the fault show up.

If the fault code relates to the precat lambda there must be a fault with the sensor or wiring.

Only thing that would screw it up is placing it in a position after a catalytic converter. Provided it has been placed in the exhaust flow somewhere before the underfloor cat there should be no associated error.  

As soon as a good sensor is fitted the code should erase automatically. That is what I would expect anyway but have you tried erasing the code just to cover that base.

Assuming code regenerates, can you confirm what sensor have you fitted and what is the error ‘P’ code please.

As the error has occured in two sensors which seems an unfortunate coincidence, there may be issue with the loom connection or associated wiring?



You say the light still comes on but have you cleared the existing fault code?

I removed the maniverter and relocated the 02 sensors and after reassembly did get a fault code and EML, but clearing the fault code erased that and it hasn’t come back since. So covering this base (which Rhino mentioned) is a must.




Thanks both I will delete the code and recheck when I get a chance this week

All done ended up replacing both sensors with second hand and all ok now Thanks everyone

Hi All, first post so here goes. 2006 Mk3 2.0. Bought the car with IL race manifold (with CAT) and Cobalt back box, standard centre pipe. Straight away got a code P0421 for PCM warm up CAT efficiency. Was recommended to put a stainless centre section in with IL sports CAT and move the second O2 sensor behind the rear CAT. Seems that the code is thrown due to different warm up time of the sensors due to new manifold. This done everything ok for 9 months.

Now have had code P0134, cleared, then two weeks later P0030 twice. Emissions are fine, rolling road is bang on 162 Bhp. Car runs perfectly.

Basically coming back to original question regarding deletion of engine management light. Any thoughts or experience of this?

Many thanks,