ECM 262A ECM-4801A, changed vacuum hose and cleared the code

[arrrxivvv]

My 2004 XC70, 201k miles, had ECM 262A (Long term fuel trim upper limit) and ECM-4801A (three way catalytic converter efficiency).
The codes are now cleared but I'd like to know if things are all good or should I dig deeper.

I replaced the evap hose assembly with the two grey check valves in the engine bay, the old hose looked cracked:
https://www.fcpeuro.com/products/volvo- ... 3cQAvD_BwE
cleared the codes,
and five miles later the 262A fuel trim code came back,
The long term fuel trim, read by a scanner, stays around almost 9%.

Then I unplugged and cleaned the MAF.
Now after 30 miles the long term fuel trim stays in between 3~4% but pretty steady.

Did I fix the problem or is there something else going on?
Is a 3~4% long term fuel trim normal?
The engine didn't seem any different before or after the repair.

On the other hand what's the life expectancy of the front oxygen sensor? Just notice that they seem pretty easy to access, and if it's due might just change it.

[enok]

I had a recurring ECM 262A with accompanying MIL light.
For a while the car has had some hesitations from time to time and the fuel consumption went from ~0.83 to 0.87 but it was still quite driveable.
After getting around to doing some proper VIDA digging i found the long term fuel trim (I part of the regulator) reached ~+14%.
Upon resetting the engine stumbled before being caught by the short term trim which went to 1.25 while the long term kept rising.
I found a huge split in the vacuum hose that goes from the intake and then separates out to different parts of the engine.
The engine probably ran fine since upon boost (2.4T) we get an overpressure in the intake that will effectively seal the leak since the split was after the check valve.

I replaced the hose and the long term trim fell to ~+1.2% before i did another reset. Haven't checked where long term trim stands after driving.

As i understand it this error is specifically for an idle state.

[jonesg]

same hose split on mine, replaced and sprayed the check valve with cleaner and blew it out with the air nozzle.
The constant MIL went out and never came back.