VW Taos Flashing CEL + Rough Idle Points to Bad Sensor

Had similar symptoms on my 2019 VW Tiguan. The engine knock sensor was indeed the culprit, causing poor performance and increased fuel consumption. The rough idling combined with flashing check engine light pointed to a serious misfire issue that needed immediate attention. The knock sensor connection had corroded, creating intermittent signal problems. This caused the engine computer to get incorrect readings, leading to improper fuel mixture and timing adjustments. This type of auto repair requires proper diagnostic equipment to verify the sensor signals. Most knock sensor issues start with either a failing sensor or damaged wiring harness. Left unchecked, this can cause significant engine damage since the computer cannot properly adjust timing to prevent detonation. For VW engines, the repair involves accessing the sensor beneath the intake manifold, replacing corroded connectors, and performing a computer reset. The flashing CEL indicates this needs attention soon to prevent potential engine damage. Best to find a shop specializing in German vehicles with proper diagnostic tools. Look for certified technicians who document their diagnosis process before starting repairs.

Thanks for sharing your experience. My Taos ended up having the exact same warning light and performance issues. The mechanic confirmed it was indeed the knock sensor causing problems with the ignition timing. Would you mind sharing roughly how much the repair cost in your case? Also curious if youve had any related issues pop up since getting it fixed. My car is running better now but I want to stay ahead of any potential problems. The fuel consumption is back to normal and the rough idle completely disappeared after the fix. Just hoping to confirm the price range was fair since repair costs seem to vary quite a bit between shops.

After getting the knock sensor fixed on my Tiguan, I paid 95€ to repair the faulty cable connection. Since the repair, my cars performance has been solid with no malfunction indicator lights or related issues. The technician found a corroded connector was causing the sensor to send incorrect signals. The fuel efficiency returned to normal right away and the engine runs smoothly now. When knock sensors act up, they often just need a wiring repair rather than full replacement, which keeps costs lower. The key is catching these car problems early before they can cause more expensive engine damage. Sounds like you got similar results with your Taos, the improved idle and normalized fuel consumption suggest they properly diagnosed and fixed the root cause. The price you mentioned seems in line with what these repairs typically cost when its just a connection issue. Based on my experience over the past year, once the knock sensor connection is properly repaired, the problem usually stays resolved. Just keep an eye on your engine performance and fuel usage to catch any changes early.

Thanks everyone for the helpful feedback. After dealing with a terrible experience at my last shop, I finally found a great mechanic through a local auto forum. They diagnosed the knock sensor issue right away and fixed it for 120€, which included new wiring and connectors. The repair process was actually smooth, dropped it off in the morning and got it back same day. The mechanic showed me the corroded wiring they replaced and explained how it was affecting the engine timing. Really appreciated their transparency. My Taos is running like new again, no more check engine warnings, rough idle is gone, and fuel efficiency is back to normal. Going to stick with this shop from now on since they did quality work at a fair price without the usual sales pressure or unnecessary add-ons. Just wanted to close the loop for anyone else dealing with similar car problems. Getting that flashing check engine light checked out quickly was definitely the right call before it could cause more serious engine damage.