CEL with fluctuating idle?

[Knox5.0]

Ok, i took a trip in my 98 Explorer 5.0 to see some family up north over the weekend. Car did great on the way up, the whole time up there, and even on the trip home. However, shortly after leaving to start home i noticed my check engine light come on. I got a little worried but the car continued to run great and ran fine all 240 miles home. When i pull in the driveway i put it in park and let the car idle for a minute. My idle was fluctuating up and down which it has never done before. I would say going between 700-1300 rpm's. Im assuming this is from whatever caused my CEL to come on.
A 30 mile section of the interstate was real rough with potholes and whatnot due to all the bad weather up there when the CEL come on so i think something got jarred loose. Anyone have a clue what would cause a CEL and fluctuating idle? Keep in mind the car still runs great and all systems seem normal except the up and down idling.

 

[Xplorer82]

Ok, i took a trip in my 98 Explorer 5.0 to see some family up north over the weekend. Car did great on the way up, the whole time up there, and even on the trip home. However, shortly after leaving to start home i noticed my check engine light come on. I got a little worried but the car continued to run great and ran fine all 240 miles home. When i pull in the driveway i put it in park and let the car idle for a minute. My idle was fluctuating up and down which it has never done before. I would say going between 700-1300 rpm's. Im assuming this is from whatever caused my CEL to come on.
A 30 mile section of the interstate was real rough with potholes and whatnot due to all the bad weather up there when the CEL come on so i think something got jarred loose. Anyone have a clue what would cause a CEL and fluctuating idle? Keep in mind the car still runs great and all systems seem normal except the up and down idling.

go get the codes read and report back. w/out them it is a Big guessing game. if you can get the codes read it'll narrow it down a lot and get you the correct info needed in a timely manner .

 

[Knox5.0]

I went to AutoZone this morning and the code he gave me was P0430. I have also noticed that my idle isnt really fluctuating anymore. Not sure why it was doing it when i got home yesterday. The only difference i guess would be that yesterday when my idle was going up and down the car had been run for 3 and a half hours non stop and today it had only been run about 10 minutes. I hope this helps get me some explainations. Thanks.

 

[Xplorer82]

w/a quick search of P0430 looks cat related. you might need to replace bank 2's cat.

P0430 Catalyst System Efficiency Below Threshold (Bank 2)

The banks are determined by the location of cylinder #1. On the V8 cylinder #1 is on the passenger side, therefore Bank 1 is on the passenger side and Bank 2 is on the driver side.

hope that helps some.

 

[Knox5.0]

I just talked to my local Ford service about this particular code. What they had to say was very interesting and i wanted to post it so people that get this code can have more answers.
My vehicle is a 98 Explorer 5.0 with 148,000 miles so this particular advice may vary with different years and models. They told me it was nothing to worry about just clear the code and forget about it. Since my car is running fine and there is no poor performance issue, they said it was more than likely due to the age of the vehicle and the mileage. They recommended running a fuel system cleaner through it and leaving it be unless i just wanted to spend money.
Im going to have the code cleared and keep an eye on things.