well all the sudden i am now getting about 130-140 miles per tank and i used to be getting about 220. and i cant; figure out why. does anyoen have any idea's ?

 

How long has it been since the car has had a tune up. I suspect a bad 02 sensor or worn our plugs and wires.

 

in may we did all new plugs wire and a cap and rotor so i'mpretty sure its not those. hmm o2 sensor?

 

Thats what I would suspect. A bad one doesn't always throw a code either. If yours an origonal it needs to be replaced anyways.

 

prolyl a dumb question i should know but where is the sensor at and how much does one usualyl cost

 

Driver side exhaust manifold, $20.

 

The oxygen (O2) sensor is located in the driver's side exhaust manifold. It's kinda hard to see sometimes from the top, but if you look down past the spark plugs, before where the exhaust manifold meets the Y-pipe, you shoud see it. They cost between $10 and $20, depending on the company. Some people have problems with the $10 Bosch sensors, and instead get the $20 AC Delco sensor, FYI.

 

is it eiser to change from the bottom of the car or from the top and how hard is it to change

 

It is easy to change. I have never changed one from the top of the car but I bet you could if your arms were long enough. Chances are it has rusted itself on there pretty good so you will need some PB blaster and a lot of levage to break it loose. You just unplug it and unscrew it. Piece of cake.

 

It depends on what tools you have available. If you all you have available is a 7/8" wrench, then you will have to get it from the bottom. If you have an oxygen sensor socket ($7-$10) and some extensions for a 3/8" ratchet, you can get it from the top.

 

why do you need to change the stock one? just kus it sucks? my gas mileage is pretty crappy once in a while... not to get off topic... but how important is changing your PCV valve? and what purpose does it serve... it might be a coincidence but it seemed as tho my car is runnig a little funny since i changed it

 

02 sensors have a lifdspan of about 50,000 to 60,000 miles. They basically bake to death over time and need to be changed. Poor mileage can almost always point to a sudden failure of the 02. It happens to all GM sensors at one point. The single wire ones that we have are especially volnerable. It is a good $20 fix that will keep your car running the way it should.

Your PVC ventalates the crank case and relieves any built up pressure. As long as the little thingy rattles in the PCV than it is fine. If you are unsure go buy a new one. It may be the cheapest part to buy.

 

hmm yea i guess ill just put the old one back in... i replaced it yesterday just because it was 2 bucks and is easier than opening your hood to your car to replace... lol.. .ill juse keep the new one for the 355 same thing prob