I just installed an AFE Cold Air Intake on my 2003 Expedition. Once installed, I started the truck and everything checked out ok. The next day, the Service Engine Soon light came on. I read all the posts in this forum about the MAF and other sensor getting dirty so I blew them off with my air hose. Light is still on.

Question is: Should I take the truck down to Ford just as a precaution?

 

Make sure you got your IAT re-installed correctly and all connections plugged back in. I know on my Camaro, if the IAT wasn't plugged back in properly, it would trip the CE light.

 

Go to an AutoZone where they have free code reading. If you take it to Ford they will charge you if the code has anything to do with the intake related parts.

 

Yes, it's sometimes hard to get that MAF sensor cable plugged bach in all the way so it makes contact, because it's so deep in the rubber bellows. Check that first. Also check the IAT sensor for the same thing. It happened to me once.

Second, if the MAF sensor is dirty, air alone won't clean it, because those wires get very hot and junk carbonizes. When engine is cold, carefuly use alcohol or acetone on a cue tip to get the carbonized junk off the wires, then air dry.

 

Thanks for the info. I contacted AFE and they said this is a common problem when first installing their air intake. They told me to unhook the negative cable on the battery for 30 minutes to reset the computer. I did this and the Service Engine light went off and remained off until I drove the car a second time. Then, the light came back on. It did the same thing again in the afternoon. Reset computer, light went off after first trip, then came back on the next time I drove the truck. Too much hassle thus far. Think I'll try Autozone next to get a free code reading.

 

Definitely have the code read. You'll take most, if not all, the guesswork out of the equation.

 

Well I got the code read at Autozone. It came up as an air vaccum problem and said to check the air bypass and idle air hoses. Did that and the light still came on so I put the stock air intake and hoses back on, reset the computer and the light is continuing to come on. Any suggestions?

 

Truck is going into the dealer on Monday.

 

I had the same thing happen when I put a K&N on. It turned out to be a bad DPFE Sensor, replaced under warranty. It sure seemed like too big of a coincidence, so I have never again used the K&N. With OE parts, 50,000 miles later, no further problem!

I think you have to be very careful when "improving" modern vehicles. I even hesitate to use anything other than Motorcraft parts in my Ford. They seem very tightly integrated such that "minor" variations sometimes cause wierd problems.

Good luck!