Hi all,

Its my first post so here goes. I need some help with the following. My wife’s MK4 Golf 2002 engine code AVU 163000km on the clock which we bought a few months ago is lurching when stopped in traffic. It is almost like it is over fueling like an o2 sensor fail but there are no warning lights on the dash.
I scanned it with my Autel 802 and came up with a few fault codes as follows including the O2 sensors. I have put in red what I believe they mean from ross-tech site

17524 Active/static
Bank1-Sensor1, Heater Circuit,Open circuit- o2 sensor 1

18010 Passive/Sporadic
Power supply terminal 30,Voltage too low- power battery/alternator

17811 Passive/Sporadic
Exhaust gas recirculation system,Control difference- ERG valve

16485 Passive/Sporadic
Mass or Volume Air Flow Circ.,Range/Performance- MAF sensor

17526 Active/static
Bank1-Sensor2, Heater Circuit,Open circuit- o2 sensor 2

16500 Active/static
Engine Coolant Temperature Sensor 1,Circuit Range/Performance- temp circuit

Now the 17524 was Oxygen sensor 1 it was the original sensor from the look of it and I have replaced this. I have not done sensor 2 yet as having trouble locating a spare. Replacing sensor 1 has helped a bit but not stopped it.

My concern is with the 17811 and 16485 codes. I think the 16485 code means the MAF sensor is gone. I tried cleaning it with the spray cleaner but it has not made a difference. Could a soak clean like I have seen online in isopropyl alcohol maybe bring it back to life?
Would a faulty ERG valve cause the problems I am seeing.

Also would not replacing the second o2 sensor cause the problems I am seeing or could it be something else like a fuse for the O2 sensors blown?

I should also point out there are no gearbox problems and no exhaust gases visible escaping that could maybe cause problems.

Any advice welcome

Many thanks

zeroasylum