Does the Octavia MkIII 1.8TSI petrol have an EGR valve.  If so where is it located on the engine?

Judging by this page, I'd say it doesn't. Scroll down about 3/4 of the way and see that there are two diagrams titled 'exhaust gas recirculation' but only for diesel engines.

LLLParts

To my knowledge, there is no EGR circuit, "EGR" is done by valve timing overlap.

Here you go, now you can see for sure that it doesn't have it.

 

Match your Engine Code, and you will see what it should have

Pages from D4B802DF3B2-1_8_132_kW_TSI__2_0_140_162_169_180_kW_TSI_engines.pdf

Thanks for the info. That's very useful to understand the configuration.

 

The reason for me asking is that I have just had the Catalytic Convertor changed as it was faulty.  The cars performance is now much better.  Two days on from leaving the garage the dreaded P0240 code (Catalyst System Efficiency below threshold (bank 1)) reappeared.  Both the oxygen sensors have been replaced in the past year also. The car is going back into the garage next week for further investigation.

 

To help me get to the bottom of this do you have any suggestions as to what to look at next.

 

17 hours ago, johnlwatts said:

The reason for me asking is that I have just had the Catalytic Convertor changed as it was faulty. 

Genuine Skoda/VW cat or aftermarket - there's been a lot of recent discussion on the Ross-Tech forum about how aftermarket cats efficiency is much lower due the lower metal content.