Everyone loves a good mystery so here's one to ponder;
Ever since my 2002 Dakota was new it has periodically set a code that could not be identified.

The truck went to many dealers with no results until one visit produced the following diagnosis;
Evap. Canister Purge Valve Solenoid Fault.

So the code was cleared and we waited,.........three months later it set the same code again,...tested the solenoid,....no fault, ...tested the purge valve,...no fault. Cleared the code again and waited.....five weeks and the code set again.

It is now 2013 and over 250 K miles, the code still sets every so often and I clear it and go on. This does not affect the running of the truck UNTIL the code sets again,, then the computer must make some adjustment and the truck runs sluggish and strange until I clear the code, after that it runs fine until the cycle repeats. I'm thinking it's a fault in the ECM programming although the ECM checks out fine.

Any thoughts on the mystery??

 

Read this

http://www.obd-codes.com/p0443

The valve may be sticking on you at times but in a test this may never show up as its only sticking at times

 

I would check for vacuum leaks, especially where the rubber lines plug in.

 

Vac lines, there,s a thought, I will run the lines. How about moisture in the vac lines or valve? Though I'v never heard of it.

 

The only other thing would be a Vacuum leak but it must be a very small leak as it tosses a code only after so long

I think its the valve its sticking at times on you every time it sticks you get the problem/code