Rough-Running Sebring Signals Rich Fuel Mixture Issue

Having experienced a similar issue with my 2004 Chrysler Stratus with the 2.4L engine, I can share some relevant information based on my experience with fuel system issues. The symptoms you describe match what I encountered, rough running, excessive fuel consumption, and hesitation during acceleration. The check engine light indicated problems with the air-fuel ratio, pointing to fuel injector issues. After diagnosis, one of the fuel injectors was found to be stuck partially open, causing the rich mixture condition. The repair involved: Complete fuel injector testing, Replacement of faulty injector, Cleaning of remaining injectors, Recalibration of the oxygen sensor readings, Final testing to ensure proper intake manifold pressure Total cost was 515€ including parts and labor. The car ran significantly better afterward, with restored power and normal fuel consumption. To provide more specific advice, please share: Engine size, Current mileage, Any recent repairs or maintenance, Specific error codes from the check engine light, Whether the problem occurs more at idle or during acceleration This information would help determine if your issue matches what I experienced with my Stratus.

Last service was at 25209 KM and the issues started shortly after. The oxygen sensor readings looked off during diagnostics, and the air filter was quite dirty when checked. The check engine light codes pointed to a rich mixture, likely due to a failing oxygen sensor affecting the air-fuel ratio. My fuel economy dropped significantly before these symptoms appeared. Did you end up replacing both oxygen sensors or just the upstream one? Also curious if cleaning the fuel injectors made any difference in your case.

Thanks for the additional details about your Sebring. In my case with the Stratus, I initially only replaced the upstream oxygen sensor since it directly affects the air-fuel ratio calculations. However, the rough running persisted until I also addressed the intake manifold system more comprehensively. The complete fix involved: Replacing the upstream O2 sensor (180€), Professional fuel injector cleaning service, New air filter replacement, Intake manifold pressure test The fuel injector cleaning made a noticeable difference in smoothing out the idle and improving acceleration. The dirty air filter was definitely contributing to the rich condition, once replaced, the engine ran much better and fuel economy improved by about 15%. My recommendation based on the similar symptoms would be to: 1. Replace the air filter first since its cheap and clearly dirty 2. Get the upstream O2 sensor replaced 3. Have the fuel injectors professionally cleaned 4. Monitor the results before considering downstream sensor replacement This systematic approach helped isolate the root cause in my case while avoiding unnecessary parts replacement. The total investment was around 400€ but solved the issues completely.

Based on the conversation flow, here is the concluding response from the original poster's perspective: Thanks for the detailed breakdown of your repair process. I went ahead and started with replacing the air filter and upstream oxygen sensor yesterday. The catalytic converter readings are better now but still not perfect. Going to have the fuel injectors cleaned next week since the rich mixture condition hasnt fully cleared up. The parts so far cost me 230€ total. Hoping the injector service fixes the remaining hesitation during acceleration. If the air-fuel ratio is still off after that, I might need to tackle the intake manifold system like you did. Will update once I have the full repair results. Really appreciate you sharing your similar experience with the Stratus, helped me avoid throwing parts at the problem out of nowhere.