Westway

Apart from a few flat spot problems in the last week or so my Lexus RX300 was working fine. Today I went to start the engine but no spark. Green Flag took it to local garage and they could not connect to the diagnostic tool. The mechanic is keeping it over night but think the ECU has failed. Could this be the problem?

I bought a 04 300rx 75,000 miles about 6 weeks ago. Great car but 2 weeks ago the engine management light appeared. Turned out to be a Lamdba sensor. Just before I took it to get repaired under the 3 month warranty I noticed a bit of a flat spot when accelerating from a stop position. Also slight hunting, I thought this would go away after the Lamdba was replaced but no such luck. I have one of the cheap ebay ODBII scanners and it is showing a fail on a rich to lean test. Anybody got any clues as this is my first Lexus. Thanks