s14 obd2: Can't pass smog because says computer not ready

[dvd]

My firend has a 96 s14 and said he couldnt pass smog because they said the ECU wasnt 'ready' He passed all the emissions tests and had replaced the maf 5 months ago. Since then he's probably put 5k miles on it since the last ecu reset. But when he tries to smog his car, the smog tech said his car isnt "ready" and said something about the cat and egr isnt ready. Anyone have any tips?

[yellow_jacket]

Make sure that the ecu has continuous power(where it should of course). And of course make sure that he doens't let the battery die at all. Other than that, a few good highway cruises usually take care of this. I can usually get the ecu to go into ready mode on the way to and from school(hour drive each way)

[dvd]

well the highway crusies should be covered. Are you saying that his battery might be affecting the problem? Maybe it doesnt have enough juices when the car is off?

[Magnes]

The idea is that the computer should run some self-tests while you drive, and it should remember these test results so that the emissions tech can verify that they have been run. If the tech says that the computer hasn't completed it's self-tests, then either the car isn't being driven in a manner which allows the tests to be completed (very unlikely) or the computer isn't remembering the completed tests (very likely).

This is where the battery comes in to play; if the computer ever loses it's power supply, it's memory will be erased. Yes that can happen with a bad battery, but it could be faulty wiring, or perhaps you are disconnecting the battery to fix stuff before taking it to the testing facility...? That kind of stuff.

[hazw8st]

Really.....

[hicas240sx]

I'm afraid you're going to have to replace the cat and the EGR because they are bad. hahahaha just kidding, I'm a smog tech from the bay area and it's funny how people fail for monitors and start replacing parts. We had a guy fail for monitors and we told him to drive around for a week and then come back and we'll see how things are, and he calls us from a muffler shop telling us he's getting a new cat and he hopes that fixes the problem. You should drive it around a little. Make sure the check engine light does NOT come on before you go back.

[s13sr20chris]

just a pointer...more than half throttle or 3500 rpm will kill a monitor for the WHOLE DRIVE CYCLE.

this means, if the ecm is testing to complete the monitor and you floor it, the ecm cancels the test and wont try again untill the car is off and cooled down again. this does not apply to all monitors but i can never remember which ones.

[dvd]

hrmm , there isnt any check engine light coming on during the drive. I'll ask about the throttle thing.

[hazw8st]

Hmmm. That's really interesting. Well, your "buddy" has 2 options. #1, troubleshoot the problem and try to fix it. Or #2, get him a "friendly" smog tech that can try to figure out the problem while it's on the rollers. Option #1 can become very costly in the long run. Option #2 should only be used as a last resort, and if the car is well tuned and has no other issues.