Fuel trims and running rich.

[nfaj]

My long term fuel trim is at about -7%. my short trim normally fluctuates but thats normal. However, I was reading on how to interpret fuel trims and the readings are normally taken at steady rpms at idle, 1500rpm, 2500rpm, and 3500rpm held for 30s. My short term fuel trim fluctuates about 5% positive to negative on idle. However, if I try to bring it up to 1500rpm not moving, it stutters/misfires as negative fuel trim jumps to -22%. NO issues when driving. No loss of power. Maybe a decrease in fuel mileage a bit. Just replaced the PCV. Under load the fuel trims are wtihin normal limits.

Anybody have any idea what this is?

Thanks

[Arith2]

When's the last time you changed your air filter?

[nfaj]

When's the last time you changed your air filter?

its new. less than 2k miles.. could it be icv?

[Arith2]

Check to see if it's opening fully.