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Hi all, I've got some technical issues with my car. The fault received for P0171 - System too lean (Bank1). I've visited several workshops as I realised many couldn't really diagnose the problem. And also researched this topic on overseas forums. Kinda giving up but I've posted my problems in overseas car forums which are quite technical but also thought of posting this here locally just in case we have gurus surfing the net also. Here's the problem: During daily cold start in the morning(avg temp 25degrees C), the engine will seems like misfiring. Stutters. If you rev it, you can hear it's like missing a beat and very quickly (within a minute) the stuttering disappears. On worse scenarios, the misfiring is so bad and the CEL will be on. OBDII scanner shows P0171 - System too lean (Bank1). Very occasionally, it will also have P0301 - Cylinder 1 misfire detected. Lets say out of 5 instances of P0171, 1-2 cases will be accompanied with P0301. I've went to a few mechanics and they suggested things like plugs, coils, which I've all changed. Plugs were initially changed to Iridium and it got worse. I threw away the plugs and bought Platinum ones and seemed better. Coils were changed with no significant differences. From the forum research, this error P0171 is related to MAF sensor. So I replaced with a brand new one. And the problem persisted exactly with no improvement. Another workshop said this could be due to fuel issues as well, ie fuel pump, fuel filter+accumulator. But I would assume if fuel is a problem, it would have also caused "P0174 System too lean (Bank2)." ?? But I've never had this P0174 error on Bank2. But ok some forumers also mentioned about the fuel delivery, so I proceeded with the change as well. Now, after I've made all these parts replacement and the fault is still recurring, the workshop is suggesting I change the injectors. From Forum, it seems injectors nowadays are seldom faulty or clogged. Even the parts shop don't seems to have ready stock for this. They said they can order this in within days but it's not a frequently changed part (ie sensors). So I'm wondering if anyone has any idea/suggestion what I should do? I'm just thinking of swapping the injectors (ie rotate injector 1&2 to 3&4) and see if it'll cause P0174 System too lean (Bank 2)?? But from my understanding, the injectors aren't that straight forward to be changed? Probably 1/2 a day's effort? Or has anyone came across this problem and can link this to any other sensors issues? I'm not sure if there's a O2 sensor in each bank? Offhand I think there's a O2 sensor for upstream and downstream.