VW Touran Sluggish: Fuel & Performance Issues Alert

Had the exact same symptoms on my 2017 VW Tiguan TDI. The engine warning light, poor fuel economy and rough acceleration pointed to faulty fuel injectors. A diagnostic scan confirmed one injector was not atomizing fuel properly, causing an incorrect air-fuel ratio and uneven combustion. The fix required removing and testing all injectors. Two were found defective and needed replacement. This is a serious issue that gets worse if ignored, it can lead to carbon buildup, damaged oxygen sensors, and potential engine damage. The repair took about 6 hours at the shop. They had to: Remove and test all injectors, Clean the injector seats, Replace faulty units with new OEM injectors, Perform injector coding, Clear fault codes, Test drive to verify proper operation After the repair, the engine ran smoothly again with restored fuel economy. This is not a DIY job due to the precision required for injector coding and the specialized tools needed for removal and testing. Best to address this quickly before it causes more extensive problems with the fuel delivery system or engine components.

Thanks for sharing your experience with the fuel injector issue. It definitely sounds like what I am dealing with. Glad to hear you got it sorted. Just curious, do you remember roughly how much the total repair cost? Also, has your check engine light stayed off since the fix, or have you noticed any other problems popping up?

Following up on the injector repair, total cost came to 515€ which included parts, labor and programming. Worth every cent since the engine now runs perfectly with the correct air-fuel ratio. The check engine light has stayed off completely since the fix. The mechanic actually showed me how one injector was causing the engine to run too rich, dumping excess fuel into the cylinder. This explained the poor fuel economy and rough running. Since replacing the faulty injector, fuel consumption is back to normal and the engine idles smoothly. No other issues have emerged in the months since the repair. The catalytic converter was checked during the service and thankfully hadn't been damaged by the rich fuel mixture. Regular maintenance like spark plugs and air filter changes will help prevent similar problems in the future. If your symptoms match what I experienced, getting those injectors tested should sort out the problem. Just make sure to use a shop with the proper diagnostic equipment for fuel system testing.

After getting this advice, I went ahead and took my Touran to a different mechanic who specializes in fuel injection systems. The diagnostic scan confirmed what others mentioned, two faulty injectors were messing up the air-fuel ratio. Total repair came to 590€, slightly more than expected but the service was thorough. They replaced both bad injectors, cleaned the intake manifold while they were at it, and recoded everything properly. The whole job took about 7 hours. The difference is remarkable, engine runs smooth now, no more check engine light, and fuel economy is back to normal. They also checked the catalytic converter which thankfully wasnt damaged from all that excess fuel. Going to stick with this new mechanic from now on. Their attention to detail and willingness to explain the whole process made a big difference compared to my previous experiences. Glad I got this sorted before it caused more extensive damage.