Stalling and bad MPG
 

Hello, newbie here, I have a 1998 Sebring Coupe LXi (son's car), and it is kicking my rear end. Two problems that persist are stalling when it comes up to temp, especially when turning right, and excessive fuel consumption. The only codes thrown are the lean condition on Bank 1 and 2. I've already done some swapnostics, MAP, TPS, CPS, checked for vacuum leaks, and frayed wires grounding out. The vehicle does have an exhaust leak downstream of the front O2 sensors. This thing is a beater with a heater, looks like the previous owner used after market upstream O2 sensors (ones without electrical connectors). Car ran excellent for almost a year before these issues started occurring.

Is it possible that O2 sensors pass vehicle diagnostics at start-up, but then fail once the car comes up to temp and starts using sensor inputs? Another thought from searching every Chrysler/Dodge forum, is the fuel pump not performing once it gets hot.....but it is definitely pumping out the fuel as I'm not getting 100 miles out of a tank of fuel and no, I have not done a fuel pressure check. Next steps? Thanks

Oxygen sensors are designed to work in pairs. The difference between the upstream sensor and the downstream sensor tells the computer how well the cat is working. As the pair ages, the computer can compensate and come up with a proper fuel-air mixture to keep the car running properly. Replacing the upstream sensor without replacing the down stream sensor can throw off this balance. It could be that the computer is believing that the mixture is too lean and is pumping extra fuel in there when in fact, it is not. This could account for the code showing lean condition and the bad gas mileage. You might consider replacing all the O2 sensors at once. People have reported bad luck with Bosch sensors so you might want to avoid them.

Stalling and Bad MPG
 

Thanks for the quick reply, do you think that may be causing my stalling issue as well as the car is basically trying to flood itself with fuel?

Could be. It must be using a heck of a lot of fuel to go through a thankful in a hundred miles.

Slight exaggeration, but I drove it to work 4 times this week, 38 miles round trip, and I have less than a qtr tank left, and you can smell it when it starts sputtering and puking. Other than that, it runs great. One day I could hear a whistling and thought how crappy the door seals were, I looked at the speedo and I was doing 80. I only paid $300 for the darn thing, but I don't know how much money I want to dump into it.

Follow-up: Fuel pump was the culprit. So I had stopped to put fuel in as I had less than a quarter tank. Car only took 8 gallons to fill...it wasn't drinking fuel, level sender is not working, purely coincidental. So that made me think, temperature related performance issues, code for lean condition, could the fuel pump be failing? I had an extra pump, it only takes a few minutes to swap out, so I changed it out. My son has been driving the hell out of it for the past several days with no issues. I think this one is solved....just waiting for the next one.

lean conditions,look for vacuum leaks,specially hoses