smokinjoe78

Hey all, i have an 05' Lariat Screw 4x4 with 133,000miles. Dealer said they gave the truck a tuneup as well as new brakes & tires. Heres my question: Previous owner installed a K&N cold air intake , but removed the edge tuner he had in there. (he left the cable that plugs into the tuner & obd2 port behind). Obviously the truck runs lean here and there throwing a misfire code. But what would happen if i install the stock airbox in the truck. Will it still run lean? also i installed a cat back flowmaster exhaust last year.

thanks for any info

sj78

06F150CFCT

It still shouldnt run lean if you put the stock unit back in....Also, a misfire code points to plugs/coils so if the dealer put in new plugs, one might have gotten fouled or you have a bad coil. I would assume the dealer didnt F up your plugs but who knows.

HoppyFX4

I think the census around here would all say that by installing the factory intake that the truck would no longer run lean. You really have two options here if you want to avoid throwing the codes...

1. Find a programmer and either run the tunes installed or buy a custom one for your K&N and Flowmasters. This will re-write the PCM and tune the engine for the extra air flow into the engine.

2. Remove the K&N, install the factory intake and enjoy. You may notice a slight decrease in throttle response, but you'll avoid anymore CIL for the engine running lean.

*Some folks may swap the K&N intake for the factory if your post in the classifieds. I hope others chime in, but with 133K you still have a lot of life left in the truck. Hope this helps!