By some weird coincidence I just had the same issue on the same car ('88 GT). No backfires but had that stumbling, gurgling exhaust note and a loss of power. Actually the first time was a couple of weeks ago. Happened in exactly the same way - under load- accelerating up hill. Had to baby it along for a while and had to accelerate very slowly to speed to avoid the stumbling but couldn't maintain more than 50 - 60 MPH. Stopped at my destination and when I left it just completely cleared up. I don't know a lot about the prior history of the car so put a bottle of injector cleaner in the tank hoping that would do the trick. I thought it had until about an hour ago when it happened again. I came here and right away found this current topic...
I haven't had the shop diagnosis of the OP but sounds good to me so I'll have a look at the tube and go with the O2 sensor for now. I do have a couple of question though... The engine in my '88 GT was swapped a few years back with a Camaro 3.4L. Will the Fiero Store or Rodney's EGR tube work for me or is it a different style, length, diameter, whatever? Is there a way to visually verify a bad EGR tube?
Also, should I get the Fiero Store special Oxygen Sensor socket too, or is that just money I can save?
1988 GT with a 3.4L V6 automatic
2006 Harley Sportster
'cause I love the twisties on two wheels or four.
[This message has been edited by Rsvl-Rider (edited 05-23-2014).]