Check Engine + Sluggish Virtus Needs Throttle Diagnosis

Had similar issues with a 2018 Polo TSI. The check engine light combined with sluggish performance pointed to a vacuum leak in the intake system. The main symptoms included engine stalling at idle and inconsistent acceleration. After inspection, the issue traced back to deteriorated vacuum hoses connecting to the throttle body. The rubber had developed small cracks, causing air leaks that messed with the engine management system. These leaks affected the air-fuel mixture, leading to idle problems and reduced performance. The fix required replacing several vacuum hoses and cleaning the throttle body. Though not a major repair in terms of components, leaving it unfixed could lead to more serious engine performance issues and increased fuel consumption over time. Worth checking the simple things first, inspect all visible vacuum hoses for cracks or loose connections. Also, a proper throttle body cleaning might help. If the idle problems persist or the engine keeps stalling, best to have a professional diagnose it with proper diagnostic tools. When these vacuum system issues start showing up around this mileage, its common to find multiple worn hoses that need attention.

Thanks for sharing that experience. Sounds exactly like what I am dealing with. After reading this, I checked my manifold pressure sensor connections and found similar deterioration in the air valve assembly. Did you remember roughly how much the repair cost? Also wondering if youve had any recurring issues since getting it fixed. My Virtus is showing the same symptoms with engine stalling and rough idle problems, so hoping I can get this sorted without too much hassle.

After taking it to the mechanic, the issue turned out to be exactly what I suspected. The air valve was malfunctioning due to a faulty hose connection from the pump. The repair cost came to 175€, which included replacing the deteriorated vacuum hoses and ensuring proper manifold pressure. Since fixing the vacuum leak, my car runs perfectly with no engine stalling or rough idle problems. The sluggish performance completely disappeared once the air intake system was properly sealed. Its been 8 months now without any recurring issues. Your symptoms match exactly what I experienced, and checking the manifold pressure sensor connections was a smart move. These vacuum hoses tend to deteriorate over time, affecting the entire air intake system. Getting it fixed promptly prevents more extensive engine problems down the line.

I took my car to a mechanic last week after reading these helpful responses. The diagnosis confirmed my suspicions about the vacuum system. Found multiple cracked hoses affecting the manifold pressure and causing those annoying idle problems. The repair bill came to 220€ total, bit more than expected but worth every cent. They replaced all the worn vacuum hoses and did a complete air intake system inspection. The mechanic showed me the old parts, and those hoses were definitely shot. The difference in performance is remarkable. No more check engine light, smooth idle, and the sluggish acceleration is completely gone. Feels like a different car now. Really glad I addressed this before it led to bigger issues. Just wish I had checked those vacuum hoses earlier when the symptoms first started. The car has been running perfectly for the past week with no signs of the previous problems. Definitely learned my lesson about staying on top of these air supply system maintenance issues.