confusing obd2 codes

[blackM5beast]

e46 318 FL

my car's been giving some problems, slight misfire at idle, and the most annoying one is where the car would lose power whilst accelerating. it would pull smooth to say 2500/3000 rpm and then suddenly have a flat spot.

i read the codes and 3 came up.

P1100 MAF Sensor Intermittent/ Check of all OBDII Systems Not Complete
P0139 02 Sensor Circuit Slow Response (Bank 1 Sensor 2)
P0012 A Camshaft Position - Timing Over - Retarded (Bank 1)

cleared them and the first one to come up was the P1100, than the P0139 and the P0012 would show as a pending code, and eventually go away or register as a code.

i then took the car to the dealer to have it fixed through SA warrenties. they read the codes and also saw the above 3.

however after they cleared the codes, the 1st one that came up were the O2 sensor one.

so now i'm confused. which of those 3 components is the culprit?

i realise that all 3 might need to be replaced, and i'm not a millionaire, so if all 3 is mulfunctioning which one do i replace first??

thanks in advance

Hi.

I feel your frustration...

Maybe this info might help u track the problem

" P1100 MAF Sensor Intermittent/ Check of all OBDII Systems Not Complete" possible causes:-

1. Poor continuity thru the MAF sensor connectors
2. Poor continuity thru the Maf sensor harness
3. Intermittent open or short inside the MAF sensor

while accessing the MAF V PID on the scan tool, lightly tap on the MAF sensor or wiggle the MAF sensor connector and harness. If the MAF V PID suddenly changes below .23 volts or above 4.6 volts, an intermittent fault is indicated.

The MAF sensor circuit is monitored by the Powertrain Control Module (PCM) for sudden voltage/airflow changes. If during the last 40 warmup cycles in key ON, engine running the PCM detects avoltage change beyond the minimum, or maximum calibrated limit a DTC (Continuous diagnostic code) is stored.

P0012 DTC trouble code may be caused by one or more of the following:

1.Incorrect camshaft timing
2.Wiring problems (harness/wiring) in intake timing
control valve control solenoid system
3.Continuous oil flow to VCT piston chamber
4.Failed timing valve control solenoid (stuck open)

Possible Solutions

The main thing to check is to verify the operation of the VCT solenoid. You're looking for a sticking or stuck VCT solenoid valve caused by contamination. Refer to vehicle specific repair manual to perform component tests for the VCT unit. Notes: Dealer techs have advanced tools and the ability to follow detailed troubleshooting steps, including the ability to test components using a scan tool.


"P0139 Oxygen Sensor Circuit Slow Response (Bank1, Sensor2)"

This involves the rear oxygen sensor on the driver's side. This code indicates the engine air fuel ratio is not being adjusted by the oxygen sensor signal or the ECM as expected to do so, or not adjusted as often as expected to do so once the engine is warmed or under normal engine use.

You will likely not notice any drivability problems, although there may be symptoms.

A code P0139 may mean that one or more of the following has happened:

1.The oxygen sensor is faulty
2.The wiring to the sensor is broken / frayed
3. There is an exhaust leak

The simplest thing to do is to reset the code and see if it comes back.

If the code comes back, the problem is more than likely the rear driver's side oxygen sensor. You will likely wind up replacing it but you should also consider these possible solutions:

Check and fix any exhaust leaks
Check for wiring problems (shorted, frayed wires)
Check the frequency and amplitude of the oxygen sensor (advanced)
Check for a deteriorating /

I hope this helps..

 

[Die_Miek]

wow, thanks for the info.

that's a whole lot of searching to do, i'll exchange my MAF with a buddy first and see what happens.

perhaps you can post the link to the site you found that info on.

thanks