Hello new here 1999 gp gt

[Coleman1]

Hello I have 99 Grand Prix naturally aspirated. Code in my car says I have a vacuum leak. Is it my o2 sensor? Ir where could it be coming from. Also I am thinking of doing a transmission rebuild car has 170,000 on it . Rebuilt engine 5,000 ,miles ago. Any suggestions. I think my clutches finally need to be replaced. Car runs on full synthetic oil and trans fluid. I have straight cat Borla exhaust system. Cold air intake. 180 t stat. Also my gas gauge went out. Sometimes it says full other times it says empty . Any suggestions?.

[02NavyBlue]

Vacuum leaks can be checked by first visually inspecting vacuum lines, then spray them (while running) with carb cleaner, brake clean, water, etc and listen for any changes in the idle. If so you've found a leak.

Why would you think the clutches are worn out in the trans? 4t65e's have gone much further.

To fix the gas gauge you will likely need to replace the sending unit inside the gas tank as the teeth on them wear out. I was having the same issue and that fixed it. (Part#: 911-008) $20 http://www.ebay.com/itm/Chevy-Buick-...f19369&vxp=mtr

[Coleman1]

Btw sorry for late reply I never get time to get online...thank you for the reply I am doing the teeth this week... Also I am going to do a trans flush..I'm due I know that much....I think I am going to replace my radiator and possibly put on a trans cooler and also a short shifter . Any advice on possible upgrades or parts I should go with. Much appreciated . -C

[Scottydoggs]

DO NOT FLUSH YOUR TRANNY! or it may die asap.

drop the pan, change the filter, add 8 new quarts of dex 3 fluid. done.

[Coleman1]

Awesome good to know!,,-C

[Russosaur]

Trans go shift kit would probably be good. I would put the 195 tstat back in tho, its really not gonna gain anything with the 180.