Can a partially clogged fuel filter be the reason for these issues?

Slightly rough idle
sluggish off the line
misfire after running perfectly fine especially when fuel is below half tank
Change in exhaust odor
less fuel efficiency

The carcis a 2010 mini s with 102k. New plugs and coils, compression is good, mashable flow sensor has been cleaned, valves blasted in the last 5k. I don't ever remember the dealer changing or suggesting the filter being replaced. Looking for a bit of insight before I pull the back seat, and yank the cover. Thanks in advance.

 

Yes. Plus, check to see if your PCV is operating correctly.

 

Sorry about the typo. Mass air flow sensor is what I was typing in the original post. Do you think a Clogged or stuck pcv would cause a random misfire on multiple cyl? And how do I check the pcv if it is built into the valve cover? Never tried it before..

 

If your PCV valve is stuck open, it certainly may cause random misfires. It causes a loss of vacuum, which will make your car run rough and sluggish. Also, remember, a random misfire code doesn't necessarily mean you are having random misfires. It means your ECU is trying to interpret what is happening under your hood. Sometimes that is a random misfire, other times it is something else that mimics that condition.
Anyhow, the easiest way to check your valve is to remove your oil filler cap while the engine is running. Hear how it starts running a little rougher? that's a little more vacuum you lost when you took the cap off. Put a stiff piece of paper over the hole. Regular printer paper should work, but if you have something just a skosh thicker, like some piece of junk mail, that'd be better. But not too thick , such as cardboard.
After about a minute, you should see this piece of paper suck down. If it doesn't, your PCV valve is probably stuck open. If you can't get a good seal across your oil filler hole, try the dipstick hole.
The PCV valve is part of the cylinder head cover, so there probably isn't a good way to clean it.. I suppose you could take the cover off, and try to clean it with carburetor cleaner from the inside. But if you go to all that trouble, you might want to replace the cover, depending on your mileage. I think they run about $350. Unfortunately, the PCV valve is integrated into the cover, so you can't just replace the valve, like you could in a "normal" car.
instructions on removing the cover here: https://www.newtis.info/tisv2/a/en/r...th-lid/Fm73zv1
Disclaimer: I'm just a shade-tree mechanic, so I'm sure those with more knowledge can jump in correct me if I give you inaccurate advice. And no feelings will be hurt.
Hopefully this will be of some help to you.

 

I am hoping that your diagnosis is correct because I ended up here as well and am about to take a closer look at the fuel filter. I looked at some pics of old fuel filters and noted that they get so beat down that they lose their form and structure. The issues seem to get worse on a full tanks as well so something is affecting the pressure in fuel delivery? BTW I see you posted this years ago, hopefully you had some eventual success in resolving the issue.
Oh yeah I have replaced the plugs and coils - fiddled with the plug gap and also started to use a little fuel injector and fuel sysstem cleaner. It seemed to make a difference although not perfect until I filled it to the top again.

 

Well, it seems like you’re doing all the right things. At your mileage, you’d probably do best to just refresh your fuel delivery system. I learned the hard way, and the long way. If you’re going to change the fuel filter ( and you should probably change it every 50k miles or so, FYI), I’d go ahead and put in a new low pressure delivery pump in at the same time, since you’re going to have the tank open anyway. (Just this once, not every time you change the filter, LOL).
and go ahead and change your HPFP, too. The price has really come down on them.

Now, I’m not that guy who says change your HPFP every time your car stutters. There’s a ton of people like THAT out there. But again, at your mileage, it’s probably about due. Especially if you think that you’re having fuel delivery problems.
And, I found out after a couple of HPFPs (I told you, I’m a slow learner&#128515, that a failing low pressure delivery pump will cause your HPFP to fail. Which, in retrospect, makes sense.
So…just do all three at the same time is my advice. The fuel filter, the low pressure delivery pump, & the HPFP. Your opinion, like your mileage, may vary. It’s probably $900 worth of parts and an afternoon, but hey, no car payment, amiright?

Also, be meticulous about how you get the filter and/or the pump seated with the rubber gasket. Sometimes it can be a real PITA. but if you don’t have it seated, not only will the car smell like gasoline, but you could have a fuel pressure problem as well. Word to the wise.

Good luck, and don’t hesitate to contact me if you run into any snags.

 

Replaced the Vanos yesterday, those rubber hoses were a challenge. Fused together.
Still running rough though. Replacing fuel filter today.