I have had code 71 (EGR gas temp too low) on my '91 for 6 years now. A while ago I did exactly as you did, for the reasons you did, had the same blockage at the throttle body as you did but cleaning only this section of the EGR system didn't clear the code. It went away for a few days but came back, just as it has done once every year - a few days after I take the fuse out to reset the light prior to going for my safety inspection! Why it takes several days of driving to reoccur is odd, but that's the way it is on my van. Presumably I still have a problem somewhere upstream.

Glad this short-cut worked in your case. Just wanted to post for others considering this that it is not a guaranteed solution. I need to clean my idle speed control valve soon, so the full EGR system service will be done at that point also. I'll be sure to post the results.

jw