Has anyone put in a aftermarket oil pressure guage?? and if so how do you trick the computer into thinking that the original is still working, so i don't get a ding ding, check guages. i am wanting to put in a mechanical guage. thanks.

You can use a Tee fitting that will allow you to install both the original sender and your aftermarket gauge. If the auto parts place doesn't have the necessary bits for it, stop by Ace Hardware. Bring your old sending unit with you (okay, you'll have to drive another car to the store ) along with the new gauge fitting so you know your Tee fitting will have the right threads to accommodate both. Use a little plumber'* tape on the threads when you screw them all together.

Temperature sending units need to be immersed in the liquid flow for best results, but you can hang pressure sensors on the end of a Tee'd piece of tubing and you'll still get accurate readings.

Thanks for your help, i went to canadian tire and found a T and fittings that will work, i just wondering if the space in the T will cause a inacurate reading, anyone know?

I assume you mean the air in the Tee? No, it will compress and the space will fill with oil soon enough. Notice if you have a mechanical gauge with a clear nylon tube that the tube fills with oil almost immediately the first time you start the engine. Your readings will certainly be accurate enough to see what'* going on.