Teach me about fuel trims and such...

[Dirtman]

More than once I've worked on a vehicle where there is a CEL and before even scanning it I popped the hood to find a aftermarket cold air intake with no provision for the fresh air side of the PVC system to connect so the owner just left it off. Put a nipple on the intake tube, hook up the line and no more CEL.

 

[bobbywalter]

Yeah Gump

Dirtball is right.

 

[Dirtman]

Hey! I'm a man! Not a ball!

 

[Uncle Gump]

Right about what? That it will set a code?

 

[Uncle Gump]

Looks like I may have to eat my words on this one...

I was confused because the metered vacuum leak from the PCV doesn't change volume if the fresh air tube is connected or not. What changes is this fresh is now not metered with the fresh air tube disconnected. When you bypass unmetered air past the throttle plate... vacuum leak.

I realize the error in my ways.... sorry dirtball.

Bobby... you always make me think harder.

 

[adsm08]

Hey! I'm a man! Not a ball!

I knew a guy in college who was both.

 

[G8orFord]

Makes sense, I guess. Thanks for the replies.