A vacuum line or better yet a vacuum tube is about a quarter inch hose, black and very flexible. You will find at least 6 of these hoses located under the hood going into and coming out of many different places. These hoses have suction when the engine is running. If a hose is unplugged from its place, it could cause a number of things to operate differently. How to find a vacuum leak? It�s not easy if you don�t have a good eye and a good ear. Look for opened tubes or unplugged nozzles where the hoses plug into or come out of. If you spot one- then put your ear close to it to notice a hissing sound coming from it. Of course be sure that the engine is running and be careful of moving and hot parts. After searching for open tube ends and listening for hissing, plug the opened ends with your finger to see if there is in fact suction coming from that tube or nozzle. You may notice a change in idle when the leak has been plugged or stopped. Good luck! Lee37726, my way of checking for leaks is to take a can of starting fluid (ether) and spray all the smaller lines, then wait 4 second for the engines reaction, then move to the next, not alot of spraying, just a fine mist for about a 2 seconds per half a foot of line, or depending on crevice of which spraying, your engine will always have a change in RPM if you have a Vacuum leak using this method, plus its cleaner and more reliable then the old take them off and check for hissing routine, but there ya go

The fuel filter is located against the firewall in a metal bracket. It is on the drivers side of the car below the brak fluid reservoir. There are two clamps and hoses on each end of the filter.

Let me know 2

Most liky, bad head gasket

overdrive is turned off. This is usually controlled by a button on the shifter knob. Press it to turn of the overdrive, push it again to turn it back on.

The answer should be in your owner's manual in the last few pages near the back.

Not much unless you take into account the standard installation versus using SRM as a client installation.

I believe it looks like mine is on the firewall to the left (passenger) side of the brake fluiid repository and behind the air filter--I plan to change mine today

Replace the Downstream O2 sensor (after the catalytic converter)

Is it the 86 or 86.5?

i believe the openings are around 6 3/4"

Your valve cover gasket is likely leaking, there are o-ring gasket around the spark plug holes that will cause oil to leak into the spark plug hole.

Have a 2000 sentra se 5spd the ecu is located in the engine compartment on the passanger side firewall. 3 screws 10mm good luck trying to get it out though! Im still trying..lol

Check the wires on the speed sensor. one or both could be loose. it is located on the rear of the engine in the middle toward the fire wall. hope this helps.

o2 sensors are in the exhaust

Usually in front of the catalytic converter near or in the exhaust manifold.

Death and disease.

LECs are local exchange companies

Yes. unless you've modded it...but a carb would just give you less performance as your engine is made to be injected.

6quarts

I've read in a few articles that first you need to get the power steering belt off. I have a 98 Sentra, and I too need to change my alternator belt (same belt as AC). After reading the articles, they say to loosen the power steering belt, you first loosen a bolt that holds the power steering pulley in place. Loosening this bolt will allow the pulley to swing closer to the engine. To cause the pulley to swing closer, there is an adjusting bolt above the pulley. The bolt has two parts. A nut on the driver side of it needs to be loosened first. Then the actual bolt (12mm) can be loosened. Loosening that bolt is supposed to swing the pulley inward which loosens the power steering belt. With the power steering belt off, you can then loosen the nut that holds the idler pulley on the alternator. (14mm) I am speaking of the idler pulley that is to the left of the AC compressor pulley. You'll see the idler pulley as being smooth. The alternator/AC belt uses its smooth side to slide along this pulley, not it's ribbed side. With that loose, the tension on the alternator belt will loosen, and you can then slip that off. That is how I have been told to do it, but I warn you, I tried this for 5 hours yesterday and could not get the power steering belt to loosen. I'm not sure what part I missed. I must have loosened the wrong bolt for the joint. It is difficult to see with the wheel well in the way. I found it easy, though, to reach my hands in there from underneathe the car with the passenger side hoisted up via a jack. My legs stuck out the front of the car. There is much easier access down there instead of from on top. Oh, don't forget, to get in there from below, you'll need to remove the splash guard which is the plastic cover. Once that is off, you'll have ready access to the alternator and power steering pulleys/belts. Best of luck on finding the step that I missed.

Oh, I forgot to add, once you loosen the idler pulley, the pulley sits upon a tensioner rod. The rod is 8mm, so an 8mm wrench is what you'll need for that. Udjusting the rod will loosen the alternator/AC belt. Just remember that you'll need to get the power steering belt off first to replace the AC/alternator belt.