Series of horrible problems.

[4ss4s1n]

I have a 97 Astro LS and ive been recently noticing some problems that keep getting worse. Such as...

1.My fuel gauge all of a sudden does not want to operate anymore,it worked fine when I was driving home one night then the next time I started it,it simply didnt mark.

2.My voltmeter began shaking violently a few days ago as well. It just keeps going left and right rapidly as if it was going to explode.

3.I recently changed my air filter with a regular fram filter. Ever since,my engine has been vibrating really rough at low rpms and the "Service Engine Soon" light somes on,it starts to smooth out once im at higher speeds,but the light stays on.

I appreciate any help you guys can give me on these problems,Ive given her regular tune ups and oil changes.These problems have all began since about two weeks ago,it seems almost like sabotage.

[yoslick]

Had this problem on a 93, voltage regulator in the alternator went bad and had all kinds of goofy electrical problems, replaced alternator and everything was a-ok!! Might want to check and see if you accidentally removed/dislocated a vacuum hose during the air cleaner change out, check the heat riser flex hose also..