P1400
Moderator
Joined: 01-23-2009
Posts: 26,490
From: Fredericksburg,VA
I still don't know where the description of the code you had in post #1 came from. I haven't seen anything like it in several searches.
Do the air intake temperature and the coolant temperature agree when cold? The IAT is part of the MAF.
The way the MAF works is: it is actually a heating coil and temp sensor, it measures the amount of air by how much electricity is required to keep the temperature steady. So, lots can go wrong.
Do the air intake temperature and the coolant temperature agree when cold? The IAT is part of the MAF.
The way the MAF works is: it is actually a heating coil and temp sensor, it measures the amount of air by how much electricity is required to keep the temperature steady. So, lots can go wrong.
Thread Starter
Senior Member
Joined: 01-07-2016
Posts: 112
From: Ashland City, tn
Well after a month and a half at this shop. Car is coming back. Code P1400 went away and only had P0171 left to deal with. The CEL is now off and code P0171 is gone for now. All he replaced was the O2 sensor (upstream) and drove it for two days putting on 30 miles or so with no code showing again. If this occurs again, could it be something due to fuse box. That is if no vac leaks found.
