This is where i heard it from, tried posting on there but that forum is slow.AllanD said:The interesting thing on 2.9's is that while the '86-87 2.9's have EGR the later 2.9's made from 1989-92 DO NOT.
You'll need the computer from the later engine (it plugs right in)
and you get the happy job of removing the EGR system.
The "thing" about EGR on the 2.9 is that the system is failure prone.
/Not so much the EGR valve itself, but the metal tube that feeds exhaust to the valve and especially the vacuum lines that the system is controlled with.
ANY sort of "failure" of the system and the relatively stupid management
decides that the situation is not good and runs the engine full rich.
The one "ugly" part that might be overlooked is that the '86-87's use a different Y-pipe and a different style mating flange to the catalytic converter.