The maf spikes when I open the throttle all the way.


Those are the long term fuel trim readings. Short term seems normal too.


I think I might ask Dave at AB what the extra nipple is. He has helped me with some issues before.

 

The left one is for the valve cover breather. (I know the clamp is loose BTW)
The right is the brake booster.
And below is the plugged nipple on my 2001.

 

That's the one in talking about. Maybe I need a better plug than my homemade version. It ran for many miles without one, but I've had it plugged for the last 4k or so.


Anyone have an idea what it's purpose is.


Thanks for the photo. I was going to upload mine once I got to a better signal area.

 

I have never seen a DII with anything hooked up to it?

Auto parts stores sell assorted plug kits that have a few different sizes.

Or you can a piece of hose from somewhere about 3" long and stick a golf tee in it for now?

 

So, I just drove to the parts store. On the initial cold start it was rougher this time. Fuel trim hit 25 on startup. Same with short term. They leveled back to around 0 after warming up and after driving hit 25 again, then back to zero once I parked.


Any ideas?


I'm still thinking the vacuum is draining somewhere. Might try a new filter. I dunno.

 

Is that positive 25%?

 

Yes, ➕ 25%.

 

Okay, then you should have lean codes. If that hole is leaking vacuum, that's probably the whole problem.

 

I'm going to find a plug for it somewhere today. I won't know until tomorrow morning's cold start if that is the fix.

 

That's really strange that you got rich codes.