Okay, I'm sorry to hear none of that helped. So let's refresh a little, you're driving and all the sudden you lose power and it won't go over 60 MPH. How often does this happen, once a week, twice a week etc? How much fuel is in your gas tank when the problem shows up? is it only at highway speeds? do you notice any other sounds or smells during the event (we'll call it that)? can you feel a shake in the driver's seat? any additional information you can provide me will be a huge help. Even if you think it's not related. This truck is quite old so that's why we're having issues figuring this out. Plus I'm not with you at the vehicle, so I can only go by what you say. So details are important. When you lose power does it always shut off, or will it stay running, just poorly? And please try to answer every question as best you can. I'd really like to get you through this and get it running correctly for you. If it stays running during the "event" try opening the hood and if possible shoot a quick video of the engine running rough.
Two more questions. how many wires does your oxygen sensor have and how many oxygen sensors can you find? There definitely should be one in front of the catalytic converter and possibly another behind it to monitor the catalytic converter efficiency. One more quick question. do you have a multimeter and know how to use it?
I do have a test plan for you. I want you to check for spark when the problem shows up. Can you do that? Also are you still having the no start issue or did that clear up with the fixed oxygen sensor? If is still a no start, try unplugging the mass air flow sensor during this time. It's on the air intake boot.
Thursday, January 7th, 2021 AT 4:57 AM