i have a code 84(EGR vacuum solenoid circuit failure) and a code 34(EVPvoltage above closed limit) when i do the koeo test. the code 84 does not present on the koer test. with the engine running the EGR vacuum solenoid gets the 12 volts continuous on the one side and i can ground the other side and the EGR valve will open to 100% and then close when i remove the ground.

question 1: since the code(84) does not present on the koer test, is this
something i need to worry about or not?

question 2: i also get a code 46(thermactor air not bypassed during self
test)
is this an intentional action on behalf of the PCM because of
the rapid WOT or is this another problem that needs to be
dealt with?

question 3: the code 34(EVPvoltage above closed limit) is present on both
tests. i just replaced the EGR sensor. is this telling me that the
EGR valve is not fully closing? i know the pin sometimes needs
to be ground down a bit to give the correct input to the PCM.

 

another question on the code 84 (EGR vacuum control solenoid failure). i unhooked the wiring harness from the ECM and did a continuity check from the vacuum solenoid to the wiring harness connector and got a good check. after hooking the harness back up, i am still getting the code 84. is that indicative of a problem with the ECM or is there something else i can look for?

 

Anytime you replace a sensor you should disconnect the battery for 5 mins. to clear & rebuild the KAM. I'd do that & drive it for 20 or so miles w/ multiple completed warmup cycles before testing again. ECU's are pretty reliable as a rule & seldom fail incrementally. When they do go, it's usually "catastrophic' failure.http://fordfuelinjection.com/?p=10 If a sensor has been "locked out " by the ECU, you need to clear the KAM before it's output is accepted again. Otherwise it repeats the code it was locked out for even after it's replaced. It will eventually drop back in by itself after 40 - 80 completed warmup cycles. Personally, I prefer to speed up the process by clearing the KAM. If a sensor is locked out, it's because it has been reporting out of range for quite a while!

 

thanks ymesik! the ecm had been disconnected for several hours and it did not change anything. i am going to try to replace the ecm if i can find a suitable replacement and see what happens then. one should be here tomorrow to stick in. thanks!

 

this is an update on my problem. hate threads that present problems and not the fix. anyway, the new computer was at the auto parts store today after i got home from work. took the old one out, put the new one in and all the codes are gone now on the koeo tests. i get a code 41 on the koer tests which i wasn't getting before, which is baffling because i put in a new HEGO sensor saturday. will have to investigate that one, but shouldn't be that hard. could be a bad new sensor or one not outputting the correct values. already ran into one brand new sensor that way. the thing wouldn't output a ohm or volt value in the specified range. think i am gonna start taking the multi tester with me and check these sensors out at the parts store before leaving with them since they don't reimburse for all the gas used making trips back and forth for their bad product. anyway, hopefully as the new computer learns the system, the code 41 will disappear on it's own. i will check it again this weekend. if worse comes to worse, i will put the old sensor back in and see what happens. i wasn't getting that code from the old computer. maybe i should have been. who knows. all this to say that i think the majority of my problems are behind me now and maybe i will start to see some fuel mileage improvement. keeping my fingers crossed. to the ones that replied to this thread, thanks a lot. it's been a learning experience that i won't soon forget.