Looks like the computer is the culprit in the driveability problems I've posted about recently. My car is 50-state emissions with EGR and uses a 556 computer.

Can anyone tell me which other computers will swap out with this one? I haven't found a used 556 locally, and for a local source where I might be able to negotiate a test/return arrangement I would rather gamble on a used one than pay all that money for a new one. My current unit is not completely dead so it would still give me a backup.

I've searched the archives. There are a a few posts about upgrades but they're vague about this swap for this car. I found a web site that shows a 561 was used on 1992 models, but it was British and I wonder whether the US models might be different because of smog testing issues.

Alternatively, are there any models of 740 or 940 that use a 556? So far I've been asking the junkyards only about units to fit 240s.

Thanks for any help you can provide.

Doug Harvey