I cannot figure out a random misfire on this lexus misfires all around and dead misses on 1 and 3 replaced plugs coils and injectors all from the dealer obd2 scanner says long term fuel trims are opposite of each other bank 1 is pulling max fuel out and bank 2 is adding max fuel there are no codes other than the misfires ive cleand all the carbon to the point where the intake and valves look new. Next i tried oxygen sensors and that didnt help, cats aren't pluged and ive swaped or ohmed out all sensors that could affect this and im lost. If you can get it to before it goes into limp mode hold it above 4500 rpm it doesn't misfire at all and sounds healthy, Ive also checked compression cold and warm and they are all in spec and very close to eachother. I bought the car this way, got it for a very good price and the car only has 120000 miles. Im leaning towards an ecu maybe someone shorted something out internally. Im lost any help would be appreciated
2008 lexus Is250 awd
Well first I would start by doing a wet and dry compression test of the engine. Some of those engines had a few problems on the 250s. Now if it's not that then it could be anything from bad injectors problem in the computer drivers of the wiring. But I'll start simple by checking the compression wet and dry to see if the engine's physically worn
After you do what Scotty if that isn't the problem Check your mass air flow and timing. Your mass airflow can be dirty or failing. The tensioner may have gone bad and the car jumped timing.
