No Cats, No Cel, Running/idling Problem

Discussion in 'SN95 4.6L Mustang Tech' started by waylon alame, Jun 23, 2014.

  1. Hello all. First off I'm new here, and
    I appreciate you all taking time to read my problem. Maybe even give me pointers to help me fix it. Lol

    ok, so I have a 03 Mustang gt with basic bolt ons.
    accufab throttle body
    cat/del X pipe with 40s.
    The o2 sensors are put back in its original spots. I just had to re thread the exhaust to get the post o2 sensors in there.
    I'm Snelling gas like no other,. And it's getting poor gas mileage. I'm not throwing any kind of check engine light and when my vehicle idles it feels a little rough at times. No all the time. But sometimes. Also if I've been driving a little while and the motor is fully heated up. If I stop somewhere like at a convenient store or something and come back out my car hesitates when starting. It will crank for a few seconds then spudder. But when I go to start it again right after the spudder it fires right up without a problem or hesitation..
    you guys have any ideas?. Like I said I'm getting no o2 cel codes or nothing
  2. Consider starting by inspecting the fuel rail pressure sensor intake vacuum reference line. Is it connected and leak free? Any raw gas in the line?
  3. Where exactly is that located at??. I'll check it tonight when I get off work.
  4. Actually. I just reran the dtcs, I'm throwing a p0161 sensor 2 bank 2 overheating.. will that cause me to run rich and idle poor?
  5. My Ford reference says "circuit malfunction". A circuit malfunction is usually a wiring FAULT. After exhaust work it's a good idea to look for melted wires.

    And yes a problem in the O2 heater circuits could cause issues.

    By chance did you do any welding on the car during the exhaust repair? Did you disconnect the battery negative?

    P0161 - HO2S Sensor Circuit Malfunction (HO2S-22)

    • Short to VPWR in harness or HO2S.
    • Water in harness connector.
    • Open VPWR circuit.
    • Open GND circuit.
    • Low battery voltage.
    • Corrosion or poor mating terminals and wiring
    • Damaged HO2S heater.
    • Damaged PCM.