Generally, EEC processors do not fail and certainly not when near-new. Sensors will sometimes fail, not the processor. That's why used auto EEC processors are cheap to buy (about $200.)- they are rarely needed. If you have a processor that fails and you wish to pay $1,000. for a replacement, be my guest.
Salesmen are notorious blowhards who will say anything for a sale or just to smooze you. If you choose to believe them, that's your option.