I wish this thread continued as I too have code 25 - Air-Fuel Ratio Lean Malfunction and 71 EGR System Malfunction.

I disconnected and plugged the vacuum lines to the EGR and dropped in the resistor, disconnected the battery, then reconnected the battery. The CEL was off for about a day, then came on soon after.

I feel a slight misfire in the way my truck drives. It is very sluggish when cruising at 1.7k rpms, then feels fine at 2k and above.

Sorry for reviving this old thread. It has been very informative.

Any information is greatly appreciated.
Go Yota!

 

 

im wanting to remove my egr valve, should i remove the whole pipe, an block off the bottom an top holes or just make a blocking plate an just block off the top hole an mout the pipe back on top of it, just trying to find out what is best method