[TinkersResto]

Hi all and I appreciate any info... Recently acquired an 02 4 door, 4x4 with the V6... Has been extremely well maintained but parked for the last 9 months. Running rough at idle, did a tune up, fresh gas, etc and is still doing it so I took it for a Code Check, it came up Bad Fuel Cap, I replaced the cap and still have the same issue and same Code.

Has anyone else had this issue and if so, what did you do to remedy it? Thanks in advance! Tinker.

 

[Dan_in_WA]

The code has to be cleared in the computer after the repair has been completed. It will take several on / off cycles before the code will disappear on its own.

Which code did the scan tool say came up? It should be a P0xxx number. And although the gas cap is the usual culprit, other things can set the same code.

Hope this helps.

 

[Rhotpursuit]

What's the actual code?

 

[TinkersResto]

I apologize for failing to add it earlier, the code the guy said was P0457 "Fuel cap loose/off".

I didn't go back by to have the codes cleared but did have the battery u hooked for @ 2 days when replacing the starter became a nightmare 🤣🤣

 

[oldeerslayer]

That P0457 is an evaporative emissions code. It will not effect how the truck runs. I just did rotor cap and plugs with all OEM parts on my 02 CrewCab and the engine runs a lot smoother. 4.3L's are touchy about what brand parts you use.
If the rough idle goes away at speed you might want to look for leaking vacuum hoses. Very common on these trucks. When you did the tune up did you remember to reconnect the breather hose on the back of the air duct above the throttle body? I forget it almost every time.

 

[Sandberm]

Maybe try a new fuel filter. I've had a few vehicles that started to run rough and a new fuel filter fixed the issue.