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Check engine codes P400 and P410

3.8K views 1 reply 2 participants last post by  aardvark  
#1 ·
Have had persistant check engine code P0400 for several years however car had been running fine. Yesterday I returned from a trip where I had left the car parked for 3 weeks and the engine ran very rough at low speed. Made it home (50 miles on interstate) but still runs rough. Error codes are
P0410 Secondary air
Po400 Air recirculation
P0300 Random misfire
P0306 Cyliner 6 misfire

Can the secondary airpump failure cause this rough idle problem?
 
#2 · (Edited)
A cylinder misfire sure can.
I would look at the coil supplying cyl 6. I've replaced 2 of the 3 coils thus far.
Your setup differs from mine in that it is a V-6 rather than inline, but the coil packs on mine have been trouble.

Oh, and on the P0400 . I get it at random, and clear the code. It goes away for a week to several months. I've cleaned and replaced all lines and the egr is not sticky.
I live with it like you have.