You might also need https://www.ebay.co.uk/itm/Lambda-O...-/263025489500?_trksid=p2349624.m46890.l49292
I think it was this that I purchased to extend lamda senor wiring. https://www.ebay.co.uk/itm/Sumitomo...-/184490983634?_trksid=p2349624.m46890.l49292
Depends what sensor it is. Normally the 2nd lamda is the white connectors Sent from my Pixel 4 using Tapatalk
Luckily you still have the piggy back cable for the first lamda on your loom. Sent from my Pixel 4 using Tapatalk
Heater and bits (unless I missed and it's part of the T25 stuff.) Have you got a coolant temp sensor and gauge, plenty on eBay or AliExpress. Also look out for a coolant burping kit, not a lot (under £25) but worth it.