VW Bora Rough Idle and Fuel Waste: Throttle Issues

I had a very similar issue with my 2003 VW Golf with the 1.6L gasoline engine. As someone with moderate experience working on VWs, the symptoms you describe match exactly what I encountered, poor fuel efficiency, rough engine idle, and inconsistent throttle response. After some troubleshooting, my mechanic diagnosed a defective accelerator pedal module, which was causing erratic throttle position readings. The repair included: Complete diagnostic scan, Testing of the throttle position sensor, Replacement of the accelerator pedal module, Basic throttle cleaning service Total cost came to 205€ and completely resolved the issues. Fuel consumption returned to normal within one tank, and the engine idle smoothed out immediately. Before suggesting this is definitely your issue, could you share: Engine size and type, Current mileage, Check engine light status, Any recent repairs or maintenance, Whether throttle response is worse at specific RPM ranges These details would help confirm if your situation matches what I experienced. The pedal module failure is common on early 2000s VWs, but similar symptoms can also indicate other throttle-related problems that should be checked.

Thanks for the detailed response. My last service was actually 2 months ago and included a full inspection, oil change, and filter replacements. The check engine light started flickering last week, and the throttle response is particularly bad between 1500-2000 RPM. The engine idle gets really unstable during this range too. Your pedal module situation sounds very similar to what I am experiencing. The air intake and throttle body symptoms match exactly. The control valve seems to react with a delay, which matches your description of erratic readings. I will have my mechanic check the throttle position sensor specifically. Good to know the repair costs were reasonable at 205€.

Good to hear back and thanks for those additional details. The flickering check engine light combined with the specific RPM range issues (1500-2000) actually strengthens my original diagnosis about the pedal module. After fixing mine, I learned that the throttle body control valve and position sensor work as a system. When the pedal module starts failing, it creates a chain reaction affecting the entire air intake management. The delayed throttle response you mentioned is a telltale sign, my car showed the exact same behavior. Quick tip from my experience: have your mechanic also check the throttle body for carbon buildup while testing the position sensor. When my control valve was acting up, it allowed irregular air flow that led to some carbon deposits. A proper cleaning along with the module replacement made a huge difference in fuel efficiency. Just track your fuel consumption after the repair. In my case, it dropped back to normal (about 7.5L/100km) within one tank of fuel, which confirmed the fix worked. The engine throttle response should also improve immediately after the repair.

Thanks for the help and thorough explanation. This matches what my car is experiencing, and I feel more confident about the repair direction now. Will follow your advice and have them check both the pedal module and clean the throttle body. Just booked an appointment for next week. The combination of unstable idle, poor throttle response, and high fuel consumption at that specific RPM range really points to the pedal module issue you described. Will make sure they inspect the entire air intake system while checking the throttle position sensor. The repair cost of 205€ seems fair for the work involved. Looking forward to getting my fuel consumption back to normal levels. Will definitely get the carbon buildup checked too since the throttle control valve issues might have caused some deposits. Thanks again for sharing your experience, saved me a lot of diagnostic guesswork.