Hello, I would like to deal with one problem with the vehicle Škoda Octavia combi 1.6 75kW, BFG, year 2003. converted to LPG in 2012 at about 120 thousand. km (now mileage 220 thousand, 20 thousand per year). The LPG system is an AC Stag 300. For the first 2 years, I did not find out when it was switched to LPG propulsion. During the third year, it happened to me once a month that the vehicle's performance slightly decreased at a speed of 140-150 km / h on LPG. This problem later appeared more often and at lower speeds, today it does me even at a speed of 30-50km / h. I have to switch to petrol at all times, because the jerk is unbearable (in addition, one car repair shop told me that the jerk could cause the engine to burn out and that it was necessary to switch to petrol immediately - was that true?). On petrol almost without a problem, a really occasional drop in power and a subsequent twitching of the gas (about 1 in 2 months). At the same time I have very bad cold starts, I have to step on the gas almost every time. And I've had a new car battery for about a month. When the car is already started, the cold suddenly increases to about 1200 rpm, the engine bumps a little for about 10-15 seconds and then the speed drops to about 900 and the engine runs quietly again. I go for LPG revisions every 10,000. km, every 20 thousand. they give me new LPG / petrol powered spark plugs. One of the possible causes of jerks is said to be engine underheating, poor tightness in the upper intake diaphragm. They told me this at a car repair shop, where they installed LPG for me, but they didn't want to. They told me that if I knew a skilled car mechanic, he would check it on me. I didn't want to change it right away due to the expensive part (upper suction approx. 5-6 thousand CZK). So I had it in a car repair shop, when I also borrowed a part of the upper intake. But the tightness of the suction was fine, so the exchange did not proceed. It's been annoying to me for over 2 years, but the really weird thing is that if something didn't seal, it wouldn't be possible for me to drive 1000km without a jerk and then again the period when it jerks. Otherwise, since the beginning of the installation, my indicator light has been on, which indicates, among other things, a fault on the lambda probe. Unfortunately, if there was a fault on the lambda probe, I probably wouldn't know it because of the constantly lit light. I'd love for someone to advise me. Because good advice is beyond gold :-)