Malfunction Indicator Light

[Sammie]

I drive a 1999 Yaris. Last week I had a new engine fitted at a cost of £750 (which I think was well worth it) and now my car sounds sweet as a nut. On Saturday afternoon my malfunction indicator light came on. It says in my handbook that this is an electrical poblem and to take it to dealer as soon as possible, so until I can get it back to garage (which will be in the next couple of days) will my car be ok to drive or not.

Any advice greatly appreciated

Thanks