If it's not really about tuning or wiring. Then it belongs in here.
i am tuning a lexus altezza with a 2jz engine on a motec m800 ecu, car has a seq gear and running 2200cc bosch injectors, lambda reads perfectly except when the throttle close after each dyno run it goes rich up to lambda 0.65 when i reopen the throttle lambda goes perfectly as tuned. I checked all the fuel tables there is no any added enrichments or any fuel compensations what could be the the problem?
Are you saying that the lambda only reads 0.65 when you're completely off the throttle? If so it would suggest that your numbers in the over run area of the fuel table are too large. A simple fix for this however would be to enable over run fuel cut.