Check Engine Light Code FF23

Joe, I’ve started a new thread for this topic.
You wrote:

“Yesterday (12/30/2019) I got a CEL with a FF23 code. Fuel supply, rich exhaust indicated. Darn! I don’t know if the EVAP system could have something to do with it. I’ve never serviced it.”

Have you cleared the code and if so, has it recurred? I have seen this code before after coasting down a long hill whilst off throttle. Cleared the code and it did not recur.

I believe FF23 is oxy sensor related. Have you replaced yours?

I had that FF23 on and off for years Joe. I tried everything and changed every sensor even the MAF.
As far as the EVAP system goes, I bought another purge valve and swapped out the carbon canister too and went as far as replacing those pricey blue valves. I replaced all the injectors and the FPR as well. Nothing made it go away permanently, It would go away for a while after a reset - sometimes for as long as a few months but always came back.
I read through the engine management .pdf FF23 pages so much I practically knew it by heart.

It did get fixed eventually, but only last spring. Tenacity!

After exhausting every known cause and swapping out all that stuff, (thank god I had a low mileage parts car!) the only possible reason for the car getting too much gas was … it was getting too much AIR. Unmetered air.

Vacuum leak. Not a big one, a very small and possibly intermittent one in my case …FF23 always got thrown with a warming engine just as it came out of open loop…never a hot car. That un-metered air must have come from a leaking intake gasket at the manifold. When the manifold came off to replace the water rail last spring, I saw the old gasket was in rough shape …probably re-used sometime in the past by the PO. New gaskets - no more FF23.

So Joe, have a look for small vacuum leaks before tearing into the evap system!

Thanks Mike. It was a continuation to Grooveman’s topic since he’s having the same-rich exhaust-problem.
Larry, I’ll look around under the hood and check as much as possible.

Joe, I see the logic there and apologize if it was presumptuous of me to start a new thread. Have you cleared the code only to have it recur?

No problem Mike. I haven’t cleared the code. Most likely I’m going to do a hard reset, look for any air leak as Larry suggested then see what happens.

I get this code in the winter whenever the PCV system clogs up from condensation caused by short trips. Cleaning the rubber hoses in the intake corrects it.

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