Took my car for fist untuned ride but have some ???'s
#1
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Took my car for fist untuned ride but have some ???'s
I took my car out for the first untuned ride with my hot cam today.I charged up the battery hooked it up started the car.It fired right up ran by it self,the first coulpe times i stopped it searched for a idle but after that it would idle pretty good by itself the SES light never came on and i drove it for about an hour.Then i shut the car off and started it the SES light was.So my question is if the computer relearns on the first ride does it not have the codes in it memory until second start.On first ride with no light would i beable to pass OBD2 emmissions test or would ECM not have enough memory
Any help or thoughts would be apprciated
Thanks BTLFEDSS
Any help or thoughts would be apprciated
Thanks BTLFEDSS
#2
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I've heard of this happening before. Yes, the PCM learns, but it seems to be too smart for it's own good and the learning goes the wrong way after a while. Big cams confuse the PCM and the O2 sensors. You need tuning to make it run right and to make it pass emissions. The SES light is probably from idle missfires. Missfire detection can be either desensitized or disabled, but you will need some software tools to do it or pay for a tune.
#3
TECH Senior Member
the SES lights will set under different circumstances for different codes... some require the problem be identified 2 times before turning the SES light on , others are based on run cycles
THe PCM is always learning... it's always adding/removing fuel at part throttle to try and run at 14.7:1 when not in PE mode.
Also on your first ride most of the readiness codes will not be set so you'll fail an OBD2 scan then , and the SES code would probably be in "Pending" status, meaning the PCM detected something strange going on, but not all the requirements have been met to actually turn the light on yet....
THe PCM is always learning... it's always adding/removing fuel at part throttle to try and run at 14.7:1 when not in PE mode.
Also on your first ride most of the readiness codes will not be set so you'll fail an OBD2 scan then , and the SES code would probably be in "Pending" status, meaning the PCM detected something strange going on, but not all the requirements have been met to actually turn the light on yet....