Whats the egr valve code on a 98 Lincoln navigator thats 4wd

Lincoln nav.
well is the engine the same size ?
it sold new with 1 of 3 engines
4.6 and 5.4, 2v and 4v. 4v is DOHC twincam head
so is 3 unique engines there, day 1. new.
so of both cars have same engine ,
and the parts counter told me it is same on 5.4L
so did rockauto.com,
if still OEM stock that is, some 3rd party sold parts might say different.
vast those.

TYPE: OBD PO401 & study the code

I think your best to have a professional use
the proper testing tools, to actually find a problem

You can throw parts at it for a long time, if you do not
understand the system your working on, or have no factory
service manuals or trouble charts to follow

I see you said you got a part replaced

So the shop failed to road test or look at data to confirm
the repair,too bad,that seems to be the problem the last 25 years

I'm going to assume the check engine light is not on, otherwise you would have checked the computer for trouble codes by now.
The computer adjusts idle speed by controlling the air going into the throttle body by way of the idle air control valve. The valve could be faulty, or the throttle body could be dirty.

Have battery tested , my truck did the same last week & it left me sitting . My battery was bad . Any auto zone or advance will check it for free

Just a couple bolts & the heat tube to loosen

Hard to get up on top of any F series Truck engine

i had the same trouble, there is a rubber boot under the cover on the top of the motor, it is coming from the egr valve, takes about 5 mins to repair and less than 5 dollars.

look for a pipe that goes from the exhaust to the intake manifold on the back.there is a valve there

Sounds like you may have a faulty cigarette lighter circuit. Bypass the lighter terminal. Or better yet, use one of those bic lighters or a match. Good luck.

egr vlve itself will cause rough idling ,stalling,stumbles during accelaration,iwould take it off clean valve ports of carbon deposits,put it back on and see,egrs are exp.enough,and like ccn7 said sounds like tps problem,but usually they give a code

is it setting any codes?
a stuck open EGR valve will cause this problem