RSQ3 Power Loss and Jerking During Acceleration Fix

Had the same symptoms on a 2016 RS3, turned out to be faulty fuel injectors causing an overly rich mixture. The main signs were identical, power loss, high fuel consumption, and jerky acceleration. This was a serious issue requiring immediate attention since bad injectors can damage other engine components if left unchecked. The diagnostic showed inconsistent spray patterns from two injectors, affecting the air-fuel ratio significantly. The fix involved replacing all fuel injectors as a set to ensure balanced fuel delivery. Also had to clean the intake manifold since the rich mixture had left carbon deposits. The spark plugs were replaced too as they were fouled from the excessive fuel. Worth checking: 1. Run a proper diagnostic scan 2. Test fuel injector spray patterns 3. Check spark plug condition 4. Inspect intake manifold for carbon buildup 5. Monitor fuel pressure These symptoms typically point to fuel delivery issues rather than catalytic converter problems. Would recommend having it checked soon to prevent potential engine damage.

Thanks for sharing your experience. My problem got fixed two months ago and it actually turned out to be a combination of failing oxygen sensor and clogged fuel injectors, causing similar symptoms. The air-fuel ratio was completely off. Did you remember the total repair cost for your fuel injector replacement? Just curious since I might need to replace mine again in the future as a preventive measure. Also, have you noticed any other issues popping up since the repair was done? In my case, they also suggested replacing the air filter during the service, but I held off on that since it was changed recently. Just monitoring the situation now but would be good to know if you faced any related problems after the fix.

Thanks for asking about the costs. The total bill for my fuel injector replacement came to 515 Euro, which included labor and parts. The mechanic identified one defective injector that was causing the rich fuel mixture, leading to all those symptoms we discussed. Since getting it fixed, the engine has been running perfectly, no more rich condition, power is back to normal, and fuel economy improved significantly. The check engine light hasnt returned and the air-fuel ratio is now spot on. No additional issues have emerged in the months following the repair. Holding off on the air filter change was probably smart if it was recently done. The main thing was addressing those fuel injectors, which really made the difference. The intake manifold showed some carbon buildup during inspection, but cleaning that was included in the service. When they tested the spark plugs, they were actually still in good shape, so we left those alone.

After my mechanic visit last week, I can confirm the issues were resolved. The failing oxygen sensor was causing incorrect readings, making the engine run with a rich mixture. Combined with partially clogged injectors, this explained all my symptoms, the poor fuel economy, power loss, and rough running. The total repair came to 380 Euro, which covered the new oxygen sensor, injector cleaning, and labor. The mechanic showed me the old sensor readings compared to the new one, and the difference was significant. My fuel economy has improved by about 20% since the fix. While they suggested replacing the air filter, I knew it was changed recently, so I skipped that service. The intake manifold looked clean enough during inspection, so no additional work was needed there. After two months of driving, the car runs perfectly, no check engine light, smooth acceleration, and proper power delivery. Really glad I got this sorted before it could cause any long-term engine damage. Just keeping an eye on the fuel consumption now to make sure everything stays optimal.