Soon2B8
Forum Member
My 98 GT was put away in January for the winter. The car ran flawlessly before putting it away. It had the stock exhaust on it at the time. Now that it's time to bring it out for the summer i'm running into some issues. I replaced the stock exhaust with a UPR o/r x-pipe and pypes m80 mufflers. After the initial install it seemed to have an exhaust leak between the passenger side manifold and x pipe so I took everything back off, bought another new gasket and gasket sealer ( did not apply sealer the first time) and reinstalled it. After that the car seemed to be running fine and it did not seem to have any leaks ( test drove around my subvision and a couple main roads). Fast forward to last night when I took it for a 10-15 mile drive the car started to not run so well. Every stop light I came to the car would idle down to the point of almost stalling and the exhaust fumes were very bad (running way rich I would think). After getting the car back home I let it idle in the drive way where it would start to pop (backfire possibly) every few minutes. I"m really worried about the idle dropping and the running rich. I need to drive the car to work tomorrow but i'm afraid its going to stall on me. Could it possibly be the upstream 02 sensors that would cause this if they are bad? Or another exhaust leak? I'm really confused and any advice would be appreciated.