WTF? is this a bad ground?
 

ok this is getting annoying now. it only used to do this once in a while but did it all friggen day today..

when i am slowing down to stop at a light if i just push the clutch in and let it drop down to idle (about 700 rpm) ill get a huge voltage drop (from almost 13-14v to very near the bottom of the gauge, like 8-9v I think, but just think 'bottom of the gauge') and my stereo cuts off and then back on, and the voltage comes back up. and I can hear the engine RPMS on the speakers if I blip the throttle. Also it doesn't happen if i keep a little throttle on when slowing down (mastered this technique in my 87 civic that would stall at anything close to idle, got that thing drank oil *reminicing*).

Other things wrong with my car?

well, it gets like 4mpg (bad 02 sensor and leaky injectors me thinks). runs rich as hell.

has 3.5k hesitation. not sure if the 5th/6th ports are working.

makes wierd noises, not really bad noises, or loud ones, but some squeaks and the fan is so friggen loud, it just makes it sound ghetto with the hood up. it's hard to explain.. if you are a car guy... it's like opening the hood of an unkempt early 80's chevy, just not a good purrrr. all the belts are fine but it still sound like somethin's squeakin!

stock exhaust sounds friggen nasty. it's got a burble to it but not a good one, maybe the cat is clogged or some crap.

various annoyances, wiper swich problem, horn no workee, not sure when and where my motor is gonna go POP! (alright im paranoid)

bah, any suggestions on any of the above?

Yup - Grounds are a likely culprit for voltage drops, hesatations, RF noise, poor mileage.
(The ECU goes nuts with flakey grounds.)

Wipers - It's probably the tiny relay inside the switch.

The horn relay rarely gives trouble, but the contacts may need cleaning or the connector pins solder joints on the circuit board could be cracked.

Exhaust noise - time for a shiny new exhaust.

The voltage dropping to anything under 12.6 volts at anytime is a bad thing. At that point, you are running on battery power only (and probably need a new battery as well if you are seeing less than 10 volts).

I would be looking at a bad alternator, before anything else.

And I have rebuilt wiper switches on my website

Squeaking.... Idler pulleys... get a can of a good wuality spreay grease with the little red straw thingy and put some right on the bearing in the idler/adjuster pully for the A/C and P/S and i'll bet your squeak will go away!!!!

Racing Beat exhaust systems are NICE :) hint hint

BUT, you have an 86 (s4)... if you take the cats off... your six ports will not function properly.... do a search for six ports and you will find TONS of posts on changing the exhaust, particularly removing the cats, and you will find lots of info.

Maybe your cat has been Gutted???, that makes a really wierd gurgling sound at idle fromt he exhaust, especially if the mufflers are old.

try reaching down and manually moving the six-port actuator shafts around to see if they are stuck open or closed.

Clean up all your ground wires, pull the o2 and eyeball it, and check the spark plugs.

what's RF noise?