Cadillac STS Throttle Issues Draining Gas & Performance

Had similar symptoms on my 2009 Cadillac CTS with the throttle valve causing inconsistent engine idle. The throttle position sensor was failing, leading to poor air intake management and terrible fuel efficiency. After proper diagnosis, the repair required replacing both the throttle body assembly and position sensor. The job took about 3 hours at the garage. This was a serious issue that needed immediate attention since it affects engine performance and safety. The symptoms matched exactly, difficult starts, erratic throttle response, and increased fuel consumption. Delaying the repair would have led to further engine damage and potentially unsafe driving conditions. A proper fix includes: Complete throttle body replacement, New throttle position sensor, Throttle body relearn procedure, Air intake system cleaning The repair solved all issues, restored normal throttle response, and brought fuel consumption back to standard levels. This is not a DIY job due to the electronic calibration requirements. Post-repair, proper maintenance includes regular air filter changes and keeping the throttle body clean to prevent similar issues.

Thanks for sharing your experience. Really glad the repair solved those throttle body problems. Just curious, what was your total repair cost for the throttle body replacement and sensor work? Also wondering if youve had any similar throttle issues pop up since the fix? My CTS is showing the exact same symptoms now with rough engine idle and poor throttle response. Trying to budget for the repair and avoid any surprises at the shop.

Just wanted to update, since getting the repairs done the car has been running perfectly with no throttle valve issues returning. The control valve system is working exactly as it should now. Total cost came to 205€ for fixing the defective accelerator pedal module, which was causing all those engine idle problems. The repair completely resolved the inconsistent air intake and poor throttle response. No more rough starting or excessive fuel consumption. The engine throttle behavior is back to normal and smooth. For your CTS showing similar symptoms, the repair costs might be in the same range if its the same issue. Make sure they do a proper diagnostic test first though, since rough idle can sometimes be caused by different throttle system components. Maintaining proper air intake system cleanliness and regular servicing has kept everything running smoothly since the fix. Its definitely worth getting it checked soon to avoid any potential damage to other engine components.

Thanks everyone for the helpful responses. Wanted to share how my repair experience turned out. Finally took my CTS to a certified shop last week after the throttle issues got worse. The mechanic found carbon buildup in the throttle body causing the erratic throttle position readings. They did a complete throttle cleaning service and replaced the faulty position sensor. Total cost was 185€ which included parts and labor. The throttle response is much smoother now and fuel efficiency has improved significantly. No more rough starts or hesitation. They also showed me the dirty throttle body before cleaning which explained the poor air intake flow. Really glad I got it fixed before it led to bigger problems. The shop did great work and even helped set up the electronic calibration properly. Going to keep up with regular air intake maintenance to prevent future issues.