I just recently (in the last 2 or 3 weeks) had my upper intake (plenum) replaced and now the last couple days when i am traveling around 30-40 and 55-65 my tach seems to be going up and down like i am pumping the gas. i have talked to a couple people who think it may be the EGR valve? also, i just had all four points alligned and my car still vibrates at speeds from around 60-75 mph what could be causing this. My front rotors are about 13 months old and my pads are maybe a month old. i thought i could get away with only changing the pads this time seeing as the rotors were only a year old when i did front brakes? any tips? i would like to get all these issues worked out in the next week or two, in three weeks i am supposed to drive to boston ( from detroit) and i really dont want to get stranded on the way there.

one more quick question...how long on average does a fuel filter last? and how hard are they to replace?

About the only thing I can help you on is the fuel filter. According to the filter I have, on the package it says to replace it every other oil change, or every 6,000 miles. They are very easy to replace, you just de pressurize your fuel line by releasing pressure at the tester on the fuel line, make sure you have a rag to catch any silled fuel, then get under there at the fuel filter (just in front of the left rear wheel) with a wrench (not sure of the size) and unscrew it on both sides, pull it out and installation is reverse of removal, it is a very easy thing to do.

Rolling right through the most populated area for members huh?

On the fuel filter, WJ is pretty close. One side is a quick disconnect the other side is a screw on. It'* actually very easy. (Hold the nut on the fuel line and turn the filter.)

The EGR if bad should be illuminating the check engine light. How old are the plugs/wires and general tune up items, O2 sensor as well?

On the vibrating, it could be a bunch of different things, from tires to wheel bearings etc.

We'd need more information to help on that one.

I'd expect the EGR to give you issues at idle and lower speeds. Besides a tune up...have you changed the tranny fluid and filter lately? Check for vacuum leaks, also.

the tranny fluid and filter have about 40,000 since they have been changed. the car just was tuned up when the upper intake got replace about a month ago...new plugs and wires then also. and yes the engine light is on

Ok..then what code is making the light stay on?

BTW..please change your title to something that is more along the lines of what the post is about.

you know i troubleshot the problem myself and i got it all fixed this afternoon. the engine light was staying on because of all the antifreeze that went into my catalytic converter when i blew my intake. i drained the transmission fluid, replaced the filter, added some of the lucas tranny additive when i put the new fluid in and it is running like a charm.