ELR MAP Sensor Symptoms Point to Performance Issues

I had a similar issue with my 2015 Cadillac CT6 Hybrid last year. As someone with moderate experience in car maintenance, I initially thought it was just the MAP sensor failing, but it turned out to be more complex. After experiencing similar symptoms, reduced engine performance, high fuel consumption, and inconsistent manifold pressure readings, I took it to my regular workshop. They discovered a significant vacuum leak in the intake system, which was causing the MAP sensor to report incorrect readings. The total repair came to 235€, which covered: Complete diagnostic testing, Vacuum system inspection, Replacement of damaged vacuum lines, MAP sensor verification, System pressure testing The automotive sensor system started working correctly after fixing the vacuum leak. My engine performance returned to normal, and the fuel economy improved significantly. Before you proceed with repairs, could you share: Current mileage on your ELR? Any recent maintenance work performed? Are you noticing any unusual sounds when accelerating? Have you checked for visible cracks in the intake manifold or vacuum lines? This information would help determine if your issue matches what I experienced or if there might be other sensor failures involved.

Thanks for sharing that experience. My ELR is at 87304 KM and just had its annual service last month. I checked the intake manifold for visible damage but found nothing obvious. The manifold pressure readings are consistently low at idle, around 15-20% below normal specs. No unusual sounds during acceleration, just the power loss. I set up an appointment with a shop that specializes in hybrid systems. Their initial quote for diagnostic testing and potential MAP sensor replacement is 320€. The interesting part is they mentioned checking the throttle position sensor too, as they've seen similar symptoms from faulty throttle sensors interacting with the car sensors system. Will update once I know more. Really hoping its just a sensor issue and not something deeper in the intake manifold assembly.

Thanks for the additional details. Having gone through the same situation with my ELR, those manifold pressure readings definitely point toward a sensor-related issue. After my experience, I strongly recommend having them check the throttle position sensor along with the MAP sensor. When my ELR showed similar symptoms around 85000 KM, the initial diagnosis focused on the MAP sensor, but the real culprit was a combination of issues. The engine performance was affected by both a failing MAP sensor and a deteriorated throttle position sensor seal that was causing irregular pressure readings. The total repair ended up including: MAP sensor replacement: 180€, Throttle position sensor cleaning and seal: 95€, System calibration: 60€ The intake manifold itself was fine, which matches what youre seeing with no visible damage. After the repair, the engine performance returned to normal, and the fuel consumption dropped back to standard levels within two tanks. Make sure the shop performs a complete pressure test of the intake system before replacing any sensors. In my case, this extra step prevented unnecessary parts replacement and helped identify the exact issue causing the sensor failure.

I appreciate the detailed response and sharing your repair experience. Those repair costs seem in line with what I was quoted. It's good to know that the engine performance issues could be resolved without major intake manifold work. The shop I'm scheduled with confirmed they'll do a complete system pressure test before any sensor replacement. They specifically mentioned checking the entire manifold pressure system and throttle position sensor as part of their diagnostic process. I'll make sure they verify all automotive sensor readings before and after any repairs. Based on your experience, I'm more confident this is likely a sensor-related issue rather than a major mechanical problem. The similar symptoms and mileage point make me think I'm dealing with the same type of MAP sensor degradation you encountered. Will definitely have them do the pressure test first, then proceed with sensor replacement if needed. The 335€ total repair cost you outlined gives me a good baseline for what to expect. Really hoping to avoid any extensive intake manifold work. Thanks again for the insights. I'll post an update once the shop completes their diagnostic testing and repairs next week.