I have a noticable miss in my car when it is in drive gear and at about 35 to 40 mph. If I drop it back into 2nd gear and get the rpm'* up then the miss seems to go away. This miss does not happen all the time but most of the time. It doesn't make much difference if it is cold or warmed up.

If I really step on the gas it doesn't seem to miss at all. The car seems to run well on the highway.

I have installed a new fuel filter, new plugs and new plug wires but that hasn't helped any.

I have found a pretty good deal on a set of ignition coil packs (I think that is what they are called) and when they come in I am going to swap those out to see if that makes any difference.

Any other thoughts would be greatly appreciated.

HI, Have you checked to see if any codes are in the system? Might be a sensor or some such.

Those would be my first guess. Also maybe check you cat to see if is is clogged. That may give similar type feel to misses sometimes.

The "service engine" light has never come on, so I have never taken the car in to have the codes run. I have no way to do that myself so I was just holding off on that step.

How do I check to see if the Cat is clogged? What process would I use to determine this? I know I could just install a new Cat converter, but I have no idea how to check out an existing one.

I appreciate the help thus far.

Simple way to check. Go under your car and tap the cat with something likea hammer (I say tap, not wind up and swing). If it is bad you may hear debris boucing around in it when you hit it.