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runs better with check engine light on?

482 Views 2 Replies 2 Participants Last post by  billgalloway5
Hey guys, i have a 2000 altima commuter car, 160,000 miles on it. Only code it will show is 0446. changed purge valve (havent changed the one on tank yet. Changed tps and maf sensors. Issue is as long as light is on it runs great, might go 2-3 weeks, then out of the blue when stopping at light it will die, it starts right back up, then light will be off. When off you never know if it will die at a stop or not! also when light is off if i am going down highway 55-60 mph and i take foot off accelerator it doesnt just smoothly slow down, you can feel it drop rpms like the motor is shut off, but it stays running! Any ideas before i consult an exorcist???
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When the computer senses something wrong it often can sub previous values "known to run right' to get car to run better when the CEL is triggered. Problem being the car may run until a certain period of time rolls over to then turn light back out if car runs better, then it has tto go through whatever software count is needed for the error to happen again (20X, 50X?) to again turn the light back on. No way of knowing what the software count is on any given thing as it is buried in the software and they change it all the time.

The CEL only comes on if that count has been hit, if not other things can be wrong but no codes logged yet as they have to hit their own counts. Hitting 'count' is what turns a soft fault into a hard one. Before that happens you have to read livedata to pick up on things going wrong that have not hit count yet.

NOW, take all that rigamarole and add it to a slight problem that shows up every now and then and you know why you need the witchdoctor.
So, full coverage and a can of gas might be the easiest and cheapest solution?
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