valve rattle and acceleration stutter

I have two problems that I don't think are related, but might be...you decide.

The most pressing issue is that if I try to accelerate with the RPMs (I have a manual trans) below 2250, the engine stutters kind of like it's missing or the mixture is too rich (or when you try to shift too early). It wasn't doing this before and started happening soon after I took it to the dealership for a service (big, big, big, mistake that I will never make again!!!).

The second issue is that, unless I have the highest octane fuel going through the engine, I get what sounds like valves rattling when the engine is under load at higher speeds.

I'm thinking I could do a few things to try and fix this: clean the MAF sensor, change plugs and wires, put in a new oxygen sensor. Thoughts?

Thanks in advance for your advice.

the noise related to fuel isn't your valves, it's spark knock. always running premium fuel in your motor isn't good for it. you're on the right track:

clean MAS
new plugs and wires if they're 50-60k old
run a bottle or 2 of fuel system cleaner
check your intake manifold bolts (upper and lower) and tighten them as needed.

there are many posts on this site about knocking and detonation. i suggest you use this site's search feature.

welcome, and good luck!

Check the vacuum line

to the fuel pressure regulator. This line boosts fuel pressure when you accelerate. Without it, the engine will knock. Maybe they did something to knock it off or are out to generate some new business. I'm also suspicious of the FPR since I had to replace the one on my 92 a couple of years ago. Cut it open and found the seat worn on one edge. Some springs are lightly off center. It would sometimes stick and cause strange problems including knocking. Ever put in a new fuel pump?

If it's the fuel system, it could also be a clogged fuel filter. If it's never been replaced it probably needs to be. I don't think it would be the fuel pump, but the FPR is a possibility.

is replacing the FPR difficult for a home mechanic w/ no training? I'm pretty adept at doing brake jobs and the like. will I need any specialized tools? is it mechanical, electric, or both? is there a way to check it's function?

Thanks.

they replaced the filter at the dealer service I had done.

Very easy to replace

I bought an aftermarket one for about $50. Two bolts hold it to the fuel rail, vacuum line pushes on, and the return line screws on. Located on the passenger side of engine. Should only take about 10 minutes and disconnect the battery to reset the computer while you are replace it. I thought mine would learn on its own but after 200 miles but it didn't. Resetting the computer did the trick. FPR is no guarantee but it can cause so many problems that are hard to diagnose that I think it is a good investment.