Check Engine light just came on today and got both of these codes. 141k miles, automatic transmission. Wondering if the combination of these two codes signifies anything specific with this vehicle. I note that both codes list "exhaust leaks" as a possible cause; the exhaust is "noisy" but not excessive. Otherwise, the vehicle appears to be running fine. Thoughts?
P0401 Possible Causes:
- EGR passage clogged
- Faulty EGR Vacuum Modulator Valve
- Faulty EGR Valve
- Faulty EGR solenoid valve
- EGR solenoid valve harness is open or shorted
- EGR solenoid valve circuit poor electrical connection
- Dead (Weak) battery
- Faulty EGR temperature sensor and circuit
- Exhaust gas leaks
P2097 Possible Causes:
- Faulty Heated Oxygen Sensor
- Heated Oxygen Sensor harness is open or shorted
- Heated Oxygen Sensor circuit poor electrical connection
- Exhaust leaks
- Contaminated Heated Oxygen Sensor
Will I start with fixing the PO401 one because that can cause the other one. The oxygen sensor just gives feedback information if the information is wrong. It'll often trip that coat even though the sensor itself is working. Prayer said easy and that you don't have two separate problems interacting and causing insane analytical problems
Hey @scottykilmer, thanks for the reply. A few days after I posted this, the alternator went completely bad and the battery drained. (Autozone confirmed dead alternator and said the battery was fine.) I replaced the alternator and the serpentine belt, did a slow charge on the battery, and everything worked fine for several days. Now the P2097 has returned, along with the new P0138 (O2 Sensor Circuit High Voltage Bank 1 Sensor 2). I'm not getting the P0401 anymore. Since you earlier advised "Fix the P0401 first", but now I'm not getting it, what would be the next best step?
EDIT: I would also like to add that the van seems to be running fine; the only "symptom" was the OBD II code. As long as there are no "physical" symptoms, is there any risk of further damage to the van? I want to fix it, but I'm currently unemployed, so I need to conserve cash.
P2097 has returned,
try the procedures here:
https://www.obd-codes.com/P2097
https://www.obd-codes.com/p0138
As long as there are no "physical" symptoms, is there any risk of further damage to the van?
yes internal problems aren't always visible/audible.
Running rich for too long can eventually cost you $2,000 in exhaust repair not to mention the extra fuel you burn.
