Just wondering if anyone else has run into this issue. I installed my Volant CAI about a month or two ago and last week got a CEL. I had the ECU scanned and it's bringing up both lean codes for each bank.

I realize the engine is now getting more air than it used to, but enough to throw a CEL?

I removed the MAF yesterday and cleaned it good with some MAF cleaner, but it didn't appear dirty at all.

The truck still runs fine, but the CEL is somewhat annoying.

I plan on having the truck tuned anyway here in a few months by Modular Depot and I know they can reflash the ECU to make use of the added incoming air, but has this happened to anyone else?

 

check all of your conections you got something not on good its sucking un measured air somewhere past the maf senser

 

The intake shouldn't cause that itself, as long as all of the incoming air is still coming through the stock MAF sensor and it is properly metering the air.
My guess is that you have something loose downstream of the MAF sensor, or the MAF sensor isn't working properly.

 

yeah i have a volant cai.. and never had a cel..

 

O2 sensors is still under the same specs. Time to change it or get the ECU re-calibrated.

 

I'll buy it if you can't figure it out.

 

I'm not very firmiliar with the Volant intake on the 4.0, but I would also take a look at where the MAF is relative to the cone filter. I know on the 5.0 mustangs guys run into trouble with how close the MAF is to the cone, where the air isn't traveling straight down the pipe and gives false readings. They even make different MAF tubes for mount an MAF next to the cone filter, or down stream near the throttle body.

 

There's a big hole in this elbow under the intake and I think that's what's causing it. It's creating a huge vacuum leak and the truck started surging so that's how I found it.