daltron

So last night the stang gave a P0345 code.

Symptoms are very occasional rough idling. It usually always happens after the engine has been running for at least 30 min. I would say it happens maybe once a week, but never with the check engine light coming on until last night. For example the last time happened in a drive thru. At the window the RPM's dropped to about 500-550 and the card sounded like it had (bad) aftermarket cams. Turning the engine off then back on fixes the issue.

Other things to note

1) Fuel pump was recently replaced
2) About two years ago "check charging system" came on (and has stayed on). However, no electrical issues or battery problems since that happened.

Any ideas on how to diagnose further?

Nuke

As far as the occasional rough idle, have you:

1. cleaned the TB?
2. replaced the fuel filter?
3. cleaned the MAF sensor?
4. ran a tank or 2 of the proper mix of SeaFoam or Techron?
5. checked the plugs?
6. checked for air in-leakage between the intake and the TB?

These are the things to start with for the idle.

As far as the "check charging system" light, if that hasn't reappeared in 2 years then I wouldn't worry about it. But if you've had any other electrical gremlins, then I'd get familiar with the TSB for the leak and verify if you have the leak or not.

daltron

TB has been cleaned
Fuel Filter was replaced in the last 5-8K miles
MAF has been cleaned
I'll try seafoam in the next tank
Plugs were replaced about 5K or so miles ago
I'll check rubber connection between TB/intake

And to clarify, the "check charging system" light has been on the last two years everyday. Since no electrical/battery problems I just assumed it was a bad sensor or something.

Nuke

With the light on continuous for 2 years with NO battery/alternator problems during that period, I can't help but suspect the dreaded water leak but hopefully, that isn't the case. Here's a link to the manual. Hopefully this will help you trouble shoot: http://iihs.net/fsm/?dir=1

daltron

I'll check out the service manual after work, thank you. What TSB is the water leak? I looked at the TSB's right now but didn't see one other than the heatercore.

Nuke

https://mustangforums.com/mustang-ts...LOOR-AREA.html

UsmcMustang

i got the same code , i changed my alternator and still nothing , im thinking of taking it to the local speed shop just to see what it is

Ps: my 345 code goes to a 301 after awhile if i dont clear it , but if i clear it it goes back to a 345 , so weird , next thing im gonna do is get new spark plugs and a new coils , anyone got a good suggestion for coils ?

chub46

Here are links for both codes.

P0345
http://www.obd-codes.com/p0345

P0301
http://www.obd-codes.com/p0301

Hope these help.

UsmcMustang

thank you , im gonna look into my ignition first , the code didnt pop up till my car was transported from socal to northern va so i dont know if it has to do anything with the temperature , also i dont have a windage tray in my car at the time so i dont know if that has anything to do with it

Aggiesrok

Have you checked the cam position sensor? It's easy to check, it's one bolt and one plug. Just swap left for right and see if it changes codes, there is a different code for each cam.