Rep Power: 0

I have a 2004 LX. I started having problems with my car being jerky especially on an incline or in higher RPMs. I took it to Advance and the associate said it didn't give him a code, that it just said something was wrong with the fuel system (sigh). So, I replaced the spark plugs & air filter and ran some sea foam through the gas tank. It was running better but I knew I needed an oil and filter change. I took it to Wal-Mart for an oil change and fuel system clean (I know people but I work there as a second job and didn't have time to do it myself *working 60+ hrs wk*) and now it is REALLY bad. It is trying to die on me while going up any incline. It is as if the engine isn't getting enough gas/power. I will run it up to 5k rpms just to make it up the hills. I don't want to f up the engine. I live in the mountains (VA) so it is really hilly. My new fuel filter just came in and I hope that helps. If not...any suggestions? Please be gentle. (I got pulled this morning doing 10 over so I could make it up the hill...bad day)

More info:
It has 179k miles. I had a tune up done about 2 years ago where they supposedly changed the spark plugs (the state of mine last week have determined that they did not). The belts look fine and not brittle, all of the hoses seem to be intact. I had muffler damage from a rock I hit about 2 years ago, it was patched and seems to be okay (could use a replacement in the next year or so). I have never had any problems out of this vehicle until the past few weeks.

 
Rep Power: 173

Oil changes take like an hour if you're taking it slooooooow!
It's sooo easy on our cars! That takes only another hour or so!

The only way you can make sure it gets done is if you do it yourself.

Maybe change the fuel filter? Its location is a pain in the *** but you don't need to do it more often than 100k miles.