4.2 Stuck in Open Loop, HELP.
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4.2 Stuck in Open Loop, HELP.
My 97 F150 4.2 5spd is stuck in open loop and gets **** gas mileage. Here is all the info I have and correct me if I'm wrong as I am a backyard mechanic.
O2 heaters aren't working [P0135], EGR is clogged [P1408]
This should not prevent system from entering closed loop (?)
- O2 heaters don't matter once warmed up
- EGR clog shouldn't affect closed loop
All O2's read around 950, fuel trims read 0. This is due to system stuck in closed loop (?)
ECT Temp Reads 87 Degrees C after running idle until fully warm
IAT reads 19 C, started at 17 C. Weather was about 18C out.
So coolant sensor looks good to me, O2 sensors don't really tell us anything in OL. I ran all new vacuum lines (except the big ones). Truck is running really rich and exhaust is ripe. What next?
O2 heaters aren't working [P0135], EGR is clogged [P1408]
This should not prevent system from entering closed loop (?)
- O2 heaters don't matter once warmed up
- EGR clog shouldn't affect closed loop
All O2's read around 950, fuel trims read 0. This is due to system stuck in closed loop (?)
ECT Temp Reads 87 Degrees C after running idle until fully warm
IAT reads 19 C, started at 17 C. Weather was about 18C out.
So coolant sensor looks good to me, O2 sensors don't really tell us anything in OL. I ran all new vacuum lines (except the big ones). Truck is running really rich and exhaust is ripe. What next?