that is debatable... agreed, you don't need them for the car to run but from a safety point of view it's a bit like disconnecting the DET sensor. I was about to take my ones off since they hadn't been connected for as long as i had the car but was convinced by a very good Zed mechanic to reconnect them. if you are going to be modding the engine and looking for more power........
I'd rather not have them fitted if I'm upping the boost since they've been known to interfere and cause boost spikes. Having no safety boost is safer than having it fitted and risking spikes IMO.
