2016 F350, can't find P0402 cause.

lmorris · July 22, 2019

I have leak tested this thing twice and taken the intake side apart once, no leaks found. Performed the reprogram and reset MAF. Replaced a slightly biased EP sensor. Checked the EP sensor tube for restrictions. Tried a known good MAF. Replaced the EGR valve. Inspected the MAP. Inspected the throttle plate. Nothing fixes this thing. Any ideas? Also I was certain the throttle plate was never used to encourage EGR flow, has this been changed?

8WA Sman · July 24, 2019

What are your readings compared to this post

lmorris · July 25, 2019

Replaced the MAP sensor and all is good. Always set after 45 minutes of driving.

Keith Browning · July 26, 2019

I have replaced a handfull of MAP sensors mostly for concerns just like this. EGR codes, boost concerns... and only one sensor showed bias when comparing PIDS. They don't have to be plugged with carbon either but they are more often than not when there is an issue. Thought I had a post on this... ahhh yessss!

lmorris · July 26, 2019

Customer drove the truck for 4 days, on his way through B.C. and the light came back on.

8WA Sman · July 27, 2019

Leon,

Has it been verified that it is the same code/

If same code how about the other sensors that share the 5 volt ref(Check for bias/KOEO) or the EGR by-pass operation & vacuum supply. Does this truck have the CCV collar kit installed?

lmorris · July 29, 2019

No, it has not been verified, truck is 1 province over from me currently. It does have the CCV collar, I installed it the first time it came in. EGR by-pass is all good. Will look into other sensors when it gets back. Who knows, maybe the owner will take it in to a B.C. dealer and they might fix it!!