Codes 113 157 172 and 173 on 94 GT

The car runs fine the majority of the time. When it does act up it seems like it's stumbling. A few days ago I just returned from a two hour dive when it just sputtered at a red light. It would barely idle, when I tried letting the clutch out it died and wouldn't start. I had it towed to a local dealer, because of the holiday weekend up here in Canada they couldn't look at it until this morning. They said it started right up and ran fine. They did pull the above codes. Any ideas what I might be dealing with?
They looked at the MAF and said it was clean.
New fuel pump
New O2 sensors
Stock engine exept for exhaust and no air pump

Thanks,

Dan
 
  • Sponsors (?)