Another vote for MSD's closed loop chip

I've had mine in for a few weeks now and the car is even more of a joy to drive than before, great fuel economy and no performance draw backs in fact the car feels stronger now. Mine is an original cat model so I already had the lambda sensor mounted in the turbo, once I set the fuel pressure and CO per Stu's instructions that was it, went for a ride keeping a close eye on my wideband monitor... perfect.

My only regret is not doing the conversion sooner.