EFI Codes got my first one

[doghows72]

Ok got my first code but I'm likeing what my mechanic buddy told me. He said the code was for PCV but then said it was due to a vacume leak between my upper and lower intake??
How would the computer know if I had a vacume leak and or does this sound like BS??
He reset the computer so no codes now and runs like a champ and I did nothing.
I should preface this by saying my check engine light came on prompting me to get the codes read.

 

[DirtDonk]

It knows about vacuum leaks because the total amount of air into the engine is metered through the Mass-Air meter. Anything that is detected over and above that, especially if it results in a lean mixture that can't be overcome by the computer adjusting the fuel delivery, will result in the know-it-all computer figuring something amiss.
That's why the PCV system has to be connected just like, or similar enough, to the factory setup so that it's working in conjunction with the rest of the controlled delivery of fuel/air.

But it seems to me it would have to be a wicked big leak for the check engine light to come on.

Is this a full Explorer build, or a hybrid of parts?
How is your PCV system plumbed?
Seems like if it was a big vacuum leak then just resetting the computer would not make such a big difference in how it ran. Should still run bad with a big leak.
At least I would think anyway. Not that I know all about this stuff and how the computer reacts to any given set of circumstances.

Good luck!

Paul

 

[doghows72]

Hey Paul, yes it is a full explorer build. PCV is the same as it was with new hoses.
The Bronco runs like a raped ape before and the same after that's why I think a vacuum leak is BS. They first told me PCV then they said a vacuum leak?
Either way that was Monday am and so far no check engine light after two days of driving?
I checked for a leak and didn't find one so if there is it must be small. Can't find one she runs great?? Guess time will tell?

 

[DirtDonk]

Yep. Gotta love those "self fixing" issues, right?%)
Better when they stay fixed too!

Paul

 

[sykanr0ng]

Does it have the OBD2 port in the cab?

Do you have a smart phone or tablet or laptop with Bluetooth?
Adding a Bluetooth dongle to a laptop that doesn't is cheap too.

You can read and keep track of what is going on with your engine if you get something like this:

https://www.scantool.net/obdlink-mxbt/

It not only reads the OBD2 codes but the Ford CAN bus codes also.

 

[904Bronco]

Did he tell you what code came up, as in number?

 

[doghows72]

No I forgot to ask. It just seemed really stupid. I'll call him and see if he remembers.

 

[Steve83]

Codes are NOT for parts. They're for electronic signals being outside the PCM's expectations or adaptations. Always read (& post) the COMPLETE code definition.

This is <$20:



There are many OBD-II definition lists online, but try to find one specific to your donor vehicle. It will be easier to understand & troubleshoot.