So, i have read and read and read all over about the po400 i am understanding that it is a conditional code rather than a actual device failure....still doesn't help my CEL. My current issue is that my 98 forester 2.5dohc automatic not only has a po400 code but also shift knocks between 1 and 2 only and also only once it is warm. seems to idle hard to when first start this all seemed to happen together at one time so trying to deduce where and what is wrong....what i've done so far...
replaced all of the vacuum lines (i mean all of them0
cleaned the BPT valve bypassed EGR solenoid valve and seems to work just fine
hooked that little green connector under steering wheel together and listened for 1.5 sec cycles of solenoids for not only EGR but pressure switching solenoid.
all seems to work there.
EGR valve works just fine engine shudders when i manually open at idle. also put vacuum gauge on EGR and holds a vacumm just fine.
I am in the understanding that the TCM controls a lot of the EGR solenoid cycle function i.e. load and stuff...however i did notice when i was checking EGR solenoid that it seemed to click allowing vacuum through to EGR when i opened the throttle but then would immediately close...is that normal? I am also thinking that something could be up with the drop resistor for duty solenoid A but I haven't wanted to start into all of that yet I just bought a innova auto-ranging meter for the purpose of hunting down the problem. I would really like some advice and help I have the service manual and have already rebuilt this engine once and i'm about to do a Fel-pro gasket conversion kit which means another engine pull in the far future. in other words I know this car very well, yet this problem eludes me.
replaced all of the vacuum lines (i mean all of them0
cleaned the BPT valve bypassed EGR solenoid valve and seems to work just fine
hooked that little green connector under steering wheel together and listened for 1.5 sec cycles of solenoids for not only EGR but pressure switching solenoid.
all seems to work there.
EGR valve works just fine engine shudders when i manually open at idle. also put vacuum gauge on EGR and holds a vacumm just fine.
I am in the understanding that the TCM controls a lot of the EGR solenoid cycle function i.e. load and stuff...however i did notice when i was checking EGR solenoid that it seemed to click allowing vacuum through to EGR when i opened the throttle but then would immediately close...is that normal? I am also thinking that something could be up with the drop resistor for duty solenoid A but I haven't wanted to start into all of that yet I just bought a innova auto-ranging meter for the purpose of hunting down the problem. I would really like some advice and help I have the service manual and have already rebuilt this engine once and i'm about to do a Fel-pro gasket conversion kit which means another engine pull in the far future. in other words I know this car very well, yet this problem eludes me.