Hey there Ford-imly, after two years of converting interior from the classic bells and whistles to an up to date basic van life style home on wheels and decided to upgrade engine piece by piece. Purchased the one and only OBD1 code reader (literally the one and only reader lol). Began replacing older parts for new motorcraft parts and slowly but surely got rid of the few codes that I got (EGR,EGR valve and TPS), when replacing TPS I cleaned throttle body from its 30yrs of build up and slapped it back in. When doing the KOEO test got a pass, however when performing the KOER test the idle was super low and start and when running the test codes 538, 411/412 came up. All are RPM related, 538= insufficient RPMs during DRT (dynamic response test) and 411/412: 11= high RPM/ 12= low. I think I’ve looked high and low in searching for some type of answers but nothing, learned some great tips from the forums as a guest enthusiast. I will admit that I didn’t go through all 650+ pages in this particular group so I apologize in advance if this topic has been brought up, as far as my issue any advice or suggestions that point into a fixable direction? Please and that you for your help!

 

Did you hit the throttle when prompted for the dynamic response test? If not, or if you didn't press it far enough this code will set. It means you didn't raise the RPM high enough with the throttle during the test.

 

I did not “floor it” is that’s what you mean. When I start the van it’s in idle really low, at that moment I’ll start the KOER test and wait for code 10 to appear which then instructs me to “turn wheel, press OD and break”. Before replacing parts and doing the KOER test the van would Rev up automatically, so do I need to perform a sequence before even doing a test?

 

It's been years since I ran a KOER test on an OBDI vehicle such as yours. There is a portion towards the end of the test where the check engine light will flash once. That's your cue to floor the accelerator and quickly let off. It comes after the turn wheel, press OD, and press brake. You don't want to break anything.

 

Did your OBDI code reader come with a user manual?

Here is one for the Innova 3145: https://csr.innova.com/Content/Manua...anual_3145.pdf

Running the KOER tests start on Page 33.

 

Yea that is the one I picked up from Amazon and did read the manual. I’ve done the sequence as instructed but I must not be doing it right, I am a visual learner and I seem to not grasp the easy written instructions. YT (YouTube) isn’t helping with any videos performing said test.

 

Upon further inspection it has now come to
my attention that there is low EGR flow detected. The EGR and connecting valve has been replaced a few months ago, could this be the sensor itself?

 

Right, the EVP sensor has a dead spot on the potentiometer most likely