What year is your lotus? The 05 has a very different emissions check system than the 06+. If you're 05, you're OK. Otherwise, it's going to be a snark to get it to work without reprogramming.
Mine is an 06'. I tried spacers, the big daddy, even tried a simulator. The 06+ checks for a dip in the emissions after throttle lift. What a pain. I was planning to build a custom simulator to match the required output. But I finally just sent the ECU out. Problem solved (and I have more torque now).
2006 Yellow Elise, BOE Torque 250, Katana II
2000 Porsche Boxster
2017 Volvo XC60
2010 Volvo XC70
2009 Chevy Express 3500 box.