21 is for the oxygen sensor reading staying at center.
No.
It does not have a maf.
There isn't a vacuum line going to the regulator on a 1998 Dodge Caravan.
DOT 3
20 gallons
A Grand Caravan would have the 41TE transmission which does not have a throttle or kickdown cable.
cant be done
Timing chain.
5 quarts
What about it? How to replace it? Replacement cost? Where to buy?
Chain
The 1998 Dodge Grand Caravan 3.8 liter engine EGR valve can be found on the top of the engine. The EGR valve will be near the back of the engine.