I installed a CAI this weekend and my truck seems to be running rough and idling high. I disconnected the battery during the install to reteach. Could the truck still be in learning mode? How long does this last. it has been 3 days and over 150 miles. I hear a high pitched sound every time the truck bogs down on me. Truck is a 08 150 w/ 800 miles on it.

Thanks,

Bob

 

Check your MAF make sure there is no debris or grease on it.

 

Because the MAF sensor is located inside the new housing, your transfer function will likely differ from stock because it changes the air flow through the sensor. The sensor is having problems determining how much air flow the engine is receiving if it's larger or has less bends than the stock tube. Prior to the 3v mod motors, Ford used MAFs inside it's own tube, so the transfer function didn't change with aftermarket intakes. The adaptive controls of the computer can only learn so much. Best bet is to get in touch with a custom tuner that has developed a transfer function for that intake system. I'd put the stock tube back on until you can get that accomplished.

 

What kind of CAI did you install?

 

Just for grins, double check that you didn't knock a vacuum line off. You mentioned a "whistle" which could be the CAI but it could also be a vacuum line off and it would also cause the symptoms you describe.

A compatibility issue with CAIs usually manifests as lean codes, pinging and such, not high idle or rough running. At least I've never heard of idle issues, but I am always willing to learn. That's why I'd look in the direction of a vacuum leak because they can produce the symptoms you describe.

As far as CAI compatibility goes, Catmonkey makes a good point. As he described, the design of the tube will change the airflow through the MAF. This can be accommodated for in the design of the tube (AEM does that for one) or via tuners. Having just spoken with Bill over at Power Hungry Performance about this, I know he can do a tune on the Gryphon to eliminate CAI compatibility issues. The CAI maker can do it too. AEM has a couple of different designs (depending on year) to eliminate problems. I know theirs is trouble free because I have one and it was. You can get similar problems (lean codes, pinging) from some "canned" tunes because they actually lean the mixture for max power. Combine a CAI with that (which tends to lean the mixture too) you can go too lean and get potentially destructive pinging. That's where the custom tuner can help.

FWIW, the stock tune runs pretty fat and has moderate timing maps, so leaning it out via a CAI usually results in some power gains (it doesn't come as much from the lack of restriction). The "tow" tunes (like level II of an Edge) are also pretty fat but with some extra timing. It's not usually enough to cause a problem with a CAI. The "Performance" level (level III on the Edge, for example) may be a problem because it has much more aggressive timing curves and is leaned out at WOT for some extra power.

From what I can determine, the better known CAI makers have pretty much eliminated compatibility issues as long as the stock tune is concerned. For that reason, if this is a CAI issue, we'd sure like to know the brand!

 

Its a K&N CAI and I had it installed in my old 07 without any problems. I pulled it out and installed it in my new 08 f-150. I also have an edge but have not installed it yet. How long is the learning? It seems to be getting better. Should I give it a couple more days?

 

I'd be under there looking for vacuum lead. You can do that by eat (i stick a small hose in my ear and run the other area arouns potential spots. You hear the hiss. Also, spraying carb cleaner around, or WD-40 will work. The engine will change pitch when it hits the leak.

If no leaks are found, and there are no issues of any other kind involved with the install, I guess giving it more time to adapt is it. I'm not familiar with K&N's kit, but the '07 and '08 are close so I doubt it's an issue of compatibility. If it worked on one, it should on the other. You could look up the part number on the K&N site and make sure the application goes to '08.

I suppose it could be the CAI, but the symptoms just don't fit IMO. Maybe someone else has seen this. I haven't. Best of luck with it!

 

Its not really that bad but I can notice it. If I am going at a constant speed like 35 mph it will feel like it misses a beat or skips. That is when I hear the high pitch sound. then all is good for a while. I dont hear the high pitch squeel all the time. And it is a very low high pitch sound like it is coming from in the cab on the drivers side. you can hardly hear it unless your listening for it.

When I did the install I used my old MFS. I just changed the MFS to the 08. I thought they would be the same but the numbers on the sensor are different. I also disconnected the battery for 30 mins again to try and start over. I also double checked all my connections and they are all good. I will try and drive it and see how it acts tomorrow. Vacuum lines look good also.

Thanks

 

oh, one other thing. I hooked the edge up to see if I could pull any codes and the edge came back with P0600 unknown. Anyone know what this code is?

Thanks,

Bob