4.0l swap smog question?

[rickcdewitt]

alright allen and makg, i know you saw this coming but i was wondering if you could advise on the differences in the smog equipment between the 2.9 and 4.0l in a second gen?what stuff should i ask for to get the whole system from the donor truck?(different style carbon canister system or something?)

 

[AllanD]

Between an '88-up 2.9 and a 90-93 4.0?

About the only difference is a control solenoid for
the Evaporative emissions control, it's called the
Cannister Purge Solenoid...

It's inline with the big vacuum line between the manifold and the charcoal cannister.

The cannister itself is identical.

Starting in 1993 the 4.0's have seperate HEGO's for each cylinder bank,
but either engine is blessedly free of complicated failure prone
emission controls.

AD