Cleaning the MAF won't help here because the fuel trims are negative. A dirty MAF would typically under-read mass air flow and subsequently force a positive fuel trim correction.
A few possibilities:
oversized fuel injectors
If the fuel injectors are pushing through more fuel than what the fuel management is expecting, this would force a negative fuel ...
I see that this was asked a month ago and got no answers, but on the off chance the poster still needs help or somebody else comes across this, I'll do my best to answer.
If you have a bank that is running too rich, which is unfortunately a very generalized condition, one or more of the following conditions must be true:
Too much fuel is being injected.
The reason was a leaky nozzle. It went well after changing the nozzle on the misfiring cylinder.
I think that the fuel enhance actually worsened or caused this situation.
I used it because I drove the car for very short distances (3km) for long time during winter, that is when the car failed the emission test.
I also had to replace the engine oil that was ...