My '98 GT was having 2 issues recently -

1. loud "squeel" at start-up &/or when the A/C comp. came on : after reading about similar sound on this forum, replaced the harmonic balancer, which was coming apart at the internal rubber ring : FIXED !!

2. she was cutting out sporadically at cruising speed; after spending big bucks on coil packs, wires, plugs, filters (no codes) I found the main battery ground cable to be loose and corroded on the block. Also removed the cheap bolt on terminal & replaced with new cable assy : FIXED !!

*Now I got a dependable daily driver ! thanks forum