VW Touran Engine Struggles with Lean Running Issues

Thanks for sharing the details about your VW Touran issue. I dealt with very similar symptoms on my 2014 VW Golf with the gas engine. I have some experience working with cars, mostly basic maintenance and troubleshooting. The symptoms you describe match exactly what I experienced, rough running, jerking during acceleration, and the check engine light. After taking it to a workshop, they diagnosed a faulty fuel injector that was causing an incorrect air-fuel ratio. The repair involved: Complete diagnostic scan, Fuel injector testing and replacement, Clearing the check engine light, Test drive to confirm fix Total cost was 515€ including parts and labor. Since the fix, the car has been running smoothly with no more jerking or power loss issues. Before suggesting this is definitely your problem, could you share: Current mileage on your Touran? Does the problem get worse when the engine is warm? Have you noticed any unusual fuel consumption? Any recent maintenance done on the throttle body or spark plugs? These details would help determine if your issue matches what I experienced or might point to something else like the EGR valve or oxygen sensors.

Thanks for clarifying, at my most recent service at 91634km, they actually checked for similar symptoms. After investigating further, it turns out my issue was related to a clogged mass air flow sensor combined with carbon buildup in the intake manifold. The engine would run rough especially during acceleration because it wasnt getting accurate airflow readings. The throttle body also needed a thorough cleaning. After addressing these issues and having the fuel injectors inspected and cleaned as a preventive measure, the car runs perfectly again with no jerking or power loss. This might point you in a useful direction for diagnosing your specific problem. The symptoms can definitely be similar when dealing with air-fuel mixture problems.

Thanks for the update on your Touran repair. Your mass airflow sensor issue is quite common, I had a similar situation with my Golf before the fuel injector problems I mentioned earlier. The connection between the throttle body, mass airflow sensor, and proper air-fuel ratio is crucial. A dirty mass airflow sensor can definitely trick the engine computer into adjusting the mixture incorrectly. The carbon buildup you mentioned can also restrict proper airflow, making the catalytic converter work harder than necessary. Since getting my fuel injectors replaced, I also started doing preventive maintenance more regularly: Cleaning the throttle body every 30000km, Using higher quality fuel with cleaning additives, Replacing the air filter on schedule, Regular EGR valve inspection The total cost for your repair sounds reasonable considering the work done. The preventive fuel injector cleaning was smart, it helps avoid more expensive repairs down the road. Would you mind sharing which fuel additives you are using now? I have been looking for recommendations since my repair.

Thanks for asking about fuel additives, but I want to stick to sharing what actually fixed my Touran. The final diagnosis showed it was indeed the clogged mass airflow sensor and carbon buildup in the intake manifold causing all those symptoms. Getting those components cleaned, plus the preventive fuel injector service, solved everything completely. The workshop also found the throttle body needed cleaning, which made sense given how the car was behaving. They mentioned these issues often occur together since dirty components in one area can affect the entire air-fuel delivery system. The repair cost totaled 420€ and included: Mass airflow sensor cleaning, Intake manifold carbon removal, Throttle body service, Fuel injector inspection and cleaning For anyone else experiencing similar rough running and power loss issues, definitely have these components checked. Getting everything properly cleaned made a huge difference in how the car runs.