T-Roc TSI Power Loss: Lean Running Engine Fixed

I had nearly identical symptoms with my 2020 T-Cross TSI last winter. As someone with moderate experience working on VW engines, I initially thought it was related to the air-fuel ratio sensor. After running diagnostics, my workshop found a faulty fuel injector that was causing uneven fuel distribution. The check engine light was triggered by the oxygen sensor detecting a lean condition. They performed a thorough inspection and found that one injector was not atomizing fuel properly, leading to incomplete combustion. The repair involved: Complete fuel injector testing, Replacement of the defective injector, System pressure testing, ECU reset and adaptation Total cost came to 515€ including parts and labor. Since the repair, the engine has been running smoothly with no power loss or rough idle issues. Before suggesting specific fixes for your case, could you share: Current mileage, When was the last fuel system service done, Are there any other warning lights besides the check engine light, Does the problem get worse when the engine is warm or cold, Have you noticed any unusual fuel consumption This information would help determine if your issue matches what I experienced with my injector problem.

Last service was completed at 112000km, now showing 114832km on the odometer. Your diagnosis matches my symptoms exactly. The workshop just confirmed a faulty fuel injector on cylinder 2. The check engine light came on because the oxygen sensor was detecting inconsistent air-fuel ratios. They also found the mass air flow sensor was giving incorrect readings, which contributed to the lean condition. Total repair came to 490€, including: New fuel injector, Mass air flow sensor replacement, System cleaning, Computer reset Car now runs perfectly with smooth acceleration and no jerking. Fuel economy has improved noticeably. The spark plugs were also inspected but found to be in good condition. Thanks for sharing your experience, it helped confirm my suspicions about the fuel delivery system being the core issue.

Great to hear you got the issue resolved! Exactly like in my case, the oxygen sensor readings pointing to the lean condition were the key indicator. These TSI engines can be sensitive to fuel delivery issues, but they are usually very reliable once the root cause is fixed. The combination of a faulty injector and mass airflow sensor explains the severe symptoms you experienced. In my case, changing just the injector was enough, but having both components fail can definitely amplify the rough running and power loss. Your repair cost was actually slightly better than mine, even with the additional sensor replacement. Since having the work done, my fuel consumption has stayed optimal and the check engine light has never returned. The catalytic converter can sometimes be affected by prolonged lean running conditions, but catching the problem relatively quickly usually prevents any secondary damage. One tip for preventive maintenance: I now have the fuel injectors cleaned professionally every 60000km. The workshop mentioned this can help prevent similar issues from developing, especially in direct injection engines like ours where carbon buildup can be more common.

Thanks for all the detailed responses about the fuel injector issue. Having both the injector and mass air flow sensor fail simultaneously definitely explains why my symptoms were so severe. The oxygen sensor readings were spot-on in identifying the lean condition. The workshop did a thorough job, their complete diagnosis helped catch both failing components before any damage occurred to the catalytic converter. The new fuel injector and mass air flow sensor have made a huge difference. Engine runs like new now with zero hesitation or power loss. Total repair of 490€ seems reasonable given the parts replaced. Good advice about preventive injector cleaning, I will definitely add that to my maintenance schedule at 60000km intervals. Better to prevent issues than deal with complete failures. Really appreciate everyone sharing their experiences with similar symptoms. Having real repair outcomes to compare against helped confirm we were on the right track with the diagnosis. The throttle body and spark plugs checked out fine, so focusing on the fuel delivery system was exactly right.