I upgraded to 784 injectors on my 2000 4.0. All was well for a while, now I'm getting an occasional P0443, Evaporative Emission Control System Purge Control Valve Circuit code.

Sometimes it'll come on even through repeated starts, then eventually it'll go away and won't come on again. Then randomly it'll flash briefly when starting, then won't come back. Then it'll appear again and stay on, through numerous restarts.

From what I've read, this code might trip because of a rich/lean running condition.

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

I haven't noticed it running poorly at all, it runs quite good as a matter of fact, but I DO notice a slight fuel odor.

Yes, I did search, and found this useful thread:
https://www.cherokeeforum.com/f2/code-p0443-94800/

BUT, none of that does me any good if this is a result of my injector upgrade...

So that's what I'm asking, is it possible my new injectors have caused this problem, or is it more likely just a coincidence?

 

Just a coincidence.. nothing to do with injectors, everything to do with EVAP system.

 

Did you get gas recently?

I figured out my 0443 was because when I was getting gas, I would top it off after the nozzle clicked. I went through 4 gas caps and all sorts of other checking until I realized it was because I was forcing too much gas into the system. I would get a CEL between full and 3/4 tank no matter how many times I would reset the code. After 3/4 tank and less it wouldn't come back on until I filled up again.
Now i just remove the nozzle when it stops, no matter what the amount, and I haven't had a code since.

 

kjc: I know it doesn't have to do with the injectors directly, but what I'm wondering is if the injectors are causing it to run too rich on start up and the evap system is freaking out. The light comes on randomly, I haven't been able to figure out any sort of pattern as to it's appearance.

mithuth: I always let it click off on it's own when I get gas, I never top off.

 

I would start with new gas cap, simple and cheap. A visual inspection around the fuel tank, looking for loose hoses, electrical connections. If all else fails, a smoke test may be in order.

 

Mopar has a problem with the coal dust in their purge canisters coming apart and the charcoal inside moves thru the lines and clogs the purge valve. I would pull these lines apart and see if you have contaminants in the line. Looks like black sand or gravel. Blow out your lines and purge valve. Then reassemble. If it happens again then you need to get a new evap can because its junk.

 

Well, the EVAP system only deals with gas fumes in your tank. Once the gas gets to the injectors the EVAP system has nothing to do with it. Now you could be running too rich at start up, and even a little rich after that, but it won't cause your evap system engine light.

 

Ok, that's what I was wondering. I didn't THINK it did, but you know, everything I know about cars I learned on old school stuff with carburetors and no computers, so this Jeep is technically the most advanced vehicle I've ever owned, if you can believe that, haha