Buick Engine Light + Power Loss: Temp Sensor Alert

I had a similar issue with my 2003 Buick LeSabre last summer. As someone with moderate experience working on cars, I initially thought it was just the sensor, but it turned out there was actually a small leak in the exhaust system near the sensor connection. The exhaust sensor replacement alone might have fixed it, but the workshop found that the leak was affecting the emission control readings, causing the engine management system to get incorrect data. This explained both the power loss and increased fuel consumption. The total repair included fixing the exhaust leak and sensor replacement, coming to 265 for parts and labor. After the fix, the engine performance returned to normal and fuel economy improved significantly. Before suggesting specific solutions for your case, could you share: Have you noticed any unusual exhaust sounds? Does the power loss occur more during acceleration or constant speed? Which specific engine code did the scan show? Any unusual smells from the exhaust? These details would help determine if your issue matches what I experienced with my Buick. Its worth checking both the sensor and surrounding exhaust components since they often work as an interconnected system.

Just had my service last week at 59871 KM and I can add some details. No unusual exhaust sounds, but the power loss is most noticeable during acceleration. The temperature fluctuation seems unusual according to the dash readings. After checking thoroughly, I noticed the heat sensor connector shows some corrosion. The engine management system throws a P0113 code consistently. No unusual smells from the exhaust component that I can detect. Thanks for the detailed response about the possible connection between the sensor and exhaust leak. This gives me a good starting point to investigate further. Would it make sense to clean the connector first before replacing the entire sensor unit to rule out a simple connection issue?

Thanks for those additional details about your Buick, this helps narrow things down. Having faced this exact situation, I can tell you that while cleaning the connector might seem like a good first step, it rarely resolves P0113 codes permanently, especially with corroded connections. When my Buick showed similar symptoms, I initially tried cleaning the exhaust temperature sensor connections, but the problem returned within a week. The engine management system continued to struggle, and the power loss during acceleration remained an issue. The corrosion you mentioned typically indicates moisture has already compromised the sensor connection. In my case, replacing the entire sensor unit proved more cost-effective than dealing with recurring issues from a cleaned but compromised connector. A few key points from my experience: The unusual temperature fluctuations you mentioned are classic signs of a failing sensor, The P0113 code combined with power loss during acceleration strongly suggests the exhaust system is getting incorrect readings, Clean connections might work temporarily but rarely solve the underlying issue Since your symptoms match my previous situation almost exactly, I would recommend going straight for the sensor replacement to avoid multiple repair attempts. The exhaust components in these models are pretty reliable overall, but the sensors tend to be a common failure point around your mileage range.

Thanks for the thorough explanation regarding sensor replacement. What you described makes complete sense, especially about the futility of just cleaning corroded connections. Since posting my question, the temperature fluctuation has actually gotten worse, so I think you are right about going straight for the full sensor replacement. I will skip the connector cleaning step and schedule the exhaust sensor replacement this week. The symptom match with your experience, particularly the P0113 code and acceleration issues, gives me confidence this is the right path forward. The engine management system seems particularly sensitive to these sensor issues. One final question, would it be worth having them do a complete emission control system check while they are working on the sensor? Given what you mentioned about potential related issues, I want to make sure we catch any developing problems while they are in there working on it.