94 Le Sabre Acting strange...need help

My 94 Le Sabre has been acting strange for a while and last December we swapped out the ECM and Crank sensor and it January the TPS.

Previous posts:

http://www.automotiveforums.com/vbulletin/showthread.php?t=636702

http://www.automotiveforums.com/vbulletin/showthread.php?t=687402


Lately the SES light will come on while driving and then when I get home, turn the car off, turn it back on, the SES light is gone. This has happened 4 times in the last 2 weeks. Mechanic thought that there would be codes stored in the ECM, yet when he runs the scanner, no codes appear at all. Last week while coming to a stop in a left turn lane, the car died completely, but I was able to come to a stop, put in park and restart. I have notice that in the last week, sometimes when you step on the brake, the RPM's will dip down rapidly below 800 and then bounce back to normal idle. I am not really sure what is going on and my mechanic is just as frustrated.

As a side note, when the SES light is on the car seems to have lost most of its glitches that have been driving me nuts for months.

Thanks

Jack

BUMP...

Update...The SES light has come on and gone off 4 times now and when the mechanic scans for the code....there is no code.