I have 2011 Chevy Malibu LT1 2.4 ecotec gas engine that needed a replacement. The mechanic Ordered and installed used engine. Got the car back ran fine but was getting check engine again after install. Code was running lean. Went back to shop so they could look at it and realized they installed a used Flex fuel engine 🤦🏻‍♂️. Then they Installed flex fuel injectors to compensate, now it’s running rich 🤑 . For the record this is a whole debacle bc I want to run regular gas not E85 like I always have. But by putting the bigger injectors and having the ECM run on original program isn’t it just gonna pull more fuel now with the over sized injectors and that in turn is why it’s running rich now. Is this feasible to make this engine run correctly. Shouldn’t they have just left the original injectors and figured out the real reason it was running lean. Bc my research finds that if you want to run normal (non-E85) fuel in a flex fuel engine, you would leave the original injectors and not have upgraded to the bigger flex injectors correct? And leave the ECM to it original programming? bc in theory upgrading the injectors and reprogramming ECM for flex would be not good running regular gas. I should bitch at this point right for a new used engine(non-flex) like my original engine was. This was their ****up. What would you do and what are your thoughts on this rich lean condition debacle. Thank you.