[alecmorgan]

My Infiniti has been acting strange for about two weeks and I am trying to figure out if it is something small or something big. It is a 2012 G25 and I bought it used about a year ago. The engine used to feel smooth, but now it hesitates when I press the pedal, almost like it coughs for a second and then catches up. It happens more when the engine is cold, like in the morning when I leave for work. Yesterday it also shook a little at the traffic light, and the fuel seems to go down faster than before. I told my cousin about it and he said, just change the spark plugs, it is the first thing to check. But my friend said that cannot be the only reason, because modern cars have many sensors and coils and the problem could be anywhere. So I am sitting in the middle again with two different answers. I checked my service papers, and I honestly cannot find any record of the plugs being changed. The car has around 94,000 kilometers, so maybe they are very old by now. I read a page from a workshop in Mussafah that explained what spark plugs do, how they light the fuel inside each cylinder, and how worn ones can cause weak power, rough idle and higher fuel use. It was simple and easy to follow, and it matched what I feel in my car. When I looked for Fast spark plugs replacement for Infiniti in Khalifa City on my phone, I mostly wanted to know if this is a quick job or if I should plan to leave the car for a whole day. I work all week and I only have Saturday free. So what do you guys think? Is it normal for the plugs to last that long, or should I have changed them already? How do you know when they are really finished, and can you check them yourself by looking at the color? I have heard some people say that the type of plug matters a lot, like iridium or the normal ones. Is it worth paying more for the better type, or is that just a way to charge extra? Also, if the workshop changes the plugs and the problem is still there, what do they check next, the coils or the injectors? I do not want to throw money at every part one by one. And one more thing, is it a big job on this engine, or only a short one? I have heard that on some V6 engines the back plugs are hard to reach and the price goes up because of the labor. If you did this on your car, please tell me how much time it took and if you felt a real difference after. Thanks everyone, I will read all the replies when I get home.