Could also be a MAF or ECT sensor, but testing would be recommended....no wait, 166k miles? If they're still the original parts, I'd change everything I could afford but especially those two since they have the largest effect on a/f ratio.
But yeah, you're on the right track. Could also be leaning out due to inadequate fuel pressure. Test the fuel pressure to be sure. My '87 did the same thing right before the fuel pump took a dump.
