A couple of things. My documentation says that a P1443 is:
P1443 - Very Small Or No Purge Flow Condition
Which absolutely could be cause by a bad filler neck grommet.
Next. Since the rich condition is being called out only on one bank we should look for "possible" causes that could affect a single bank. IMO that rules out high fuel pressure. In the same vein that rules out a MAF problem.
IMO we are not looking at an exhaust leak on one side as the PCM would view that as a LEAN condition. In the same vein we are not looking at an intake vacuum leak on one side as this shows up as a LEAN.
What are the typical "causes" for a RICH condition affecting a single bank? What comes to mind:
- Bad O2 sensor on one bank
- uneven injector flow rates between the cylnders
- Base motor timing. Think timing chain slip from one bank to the other.
- other base motor problem such as leaking valves.
I am a big believer in Occam's Razor. https://en.wikipedia.org/wiki/Occam%27s_razor
The car runs well. So it follows that the PCM's fuel control (the O2 sensors) are working well. While I believe this should be confirmed it makes sense on the surface. But we know that the motor IS running rich because of the SMELL of fuel.
Has any recent motor work been done? Back to the fact the motor runs well. IMO that would tend to rule out a base motor timing issue.
Sooooooooooooo if looking for the simplest single possible "cause" that matches all of the symptoms. Drum roll................
How about a clogged single injector? Or it's cousin an injector with excessive flow? IMO the lean injector makes slightly more sense as the O2 sensor will see the air from the lean cylinder and the PCM will respond by adding fuel. But the PCM can only increase fuel on the entire bank. This results in way more fuel going into the exhaust. The DTC is set when the PCM feels it's no long able to control the Air fuel mixture using it's feedback methods.
I personally have had great success using InjectorRX.com cleaning and flow test service. Once cleaned and tested they are as good as new. Cheaper than new. The best part is the report that list what the injectors flowed before and after testing. IF you keep track of which cylinder each injector came from this could make it possible to confirm the repair.