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My 2006 Civic recently started sputtering when I'm driving in traffic, going around 50-55 mph it sputters 2-3 times and then it runs normal. I was going up a hill a few days ago and all of a sudden my yellow engine light started blinking and I lost power. I guess the car went into some kind of reduced power mode. I was able to park the car, came back an hour and a half later and it started up and there was no blinking engine light. I took the car to the garage and the mechanic said it was showing no codes. I changed the air filter, spark plugs and cleaned the mass air flow sensor. Nothing changed. Not sure where to go next. Any help would be appreciated.

 
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Monitor fuel pressure as misfires happen and get a freeze frame or live data reading when check engine light is blinking.

 
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Sounds like a plan. Not sure what's going on , but the last 3 days of normal driving and the car didn't sputter once. Looks like it will be a work in progress. Thanks for the advice.