97 Explorer EGR Flow & Heater Circuit Malfunction Help

[ranleyos]

I hope someone out there can help me diagnose this problem that I have been having with my 97 Explorer.

I haven't driven my truck for a while, but recently my wife drove the truck on a longer trip. While returning, my wife and the other passengers noted that the engine began to lose power, started to "choke" and there was even a electrical-burning smell that was overwhelming. They stopped and I went to pick them up in the car and drive the truck home (the electrical burning smell was so bad they were thinking the truck would catch fire). On the way home, I kept the RPMs low and did not notice any of issues. I reset the engine light and it did not come back on until the next day.

When it did return, the engine again felt like it was choking. So, I got the error codes:

P0141 Heater Circuit Malfunction
P0401 EGR Flow Insufficient

Does anyone have any idea? I believe I've had EGR problems before on this truck and replaced the EGR valve. Could the Heater Circuit Malfunction error code cause the electrical burning smell?

Any ideas on how to fix this? Thanks in advance!

[theoldwizard]

P0141 - HO2S Heater Circuit Bank 1 Sensor 2

I think the is the left (driver side) rear EGO. Check the wiring going to it. It might be the source of the burning electrical smell.

The other problem could just be plugged EGR passageways, typically just behind the throttle body.

[cjones]

bank 1 O2 sensors are on the exhaust side with the #1 cyl. in this case the passenger side. if you have single exhaust then B1S2 would be the only sensor after the cat.

what engine do you have?? 5.0L or 4.0L?? if 4.0L what's the 8th digit of the VIN?? so i/we can give more detailed instructions for the codes.

oldwizard, didn't want to step on your toes. take care, CJ

[ranleyos]

Thank you both for you help. The engine is a 4.0L Pushrod V6. Sorry, I should have specified that.

[cjones]

P0141;
as the oldwizard said...visually inspect the wiring for that O2 sensor.

if ok, check for 12v at VPWR and SIGRTN (see pic).

also, check MiniFuse 11 15Amp.

P0401;
check for disconnected hoses and connectors for EGR system.