I had a code come up for maf sensor, I inspected and found a cracked cold air hose Crack. I replaced the hose and cleared the code. Today another code came up too much air and egr excessive air flow. I replaced the maf sensor because the truck was running fine after I unplugged the harness. Drove about 20 miles and unplugged the sensor and truck still runs fine, codes are cleared and no cel. But the codes are permanently stored in ob2. Shouldn't the truck shut off when I unplug the maf sensor?

 

Nope, it'll run all day long without the MAF plugged in, but fuel economy may be in the toilet.

 

fuel economy is great about 20mpg

 

Egr codes use MAF data

when egr opens, MAF is expected to drop

perm codes can’t be manually cleared…the pcm clears them once the code condition is verified as resolved.

i dont understand what you are doing.. nothing on a 6.7 is fixed by disconnecting sensors , driving with unconnected sensors, then reconnecting sensors.

 

I disconnected it to see if the truck would stop running to check if the maf was bad, but plugged it back in. I changed the maf and so far light stayed off.