Hey so i just picked up a scan tool today cause my check engine light was on. These are the errors i got

18010-163
power supply terminal 30: low voltage

17606-035
oxygen heater circuit: B1 S2

17607-035
oxygen heater circuit: B2 S2

17604-035
oxygen heater circuit: B1 S1

17605-035
oxygen heater circuit: B2 S1

16518- 163
oxygen sensor B1 S1 malfunction : p0134

16538- 163
oxygen sensor B2 S1 malfunction : p0154

16524- 163
oxygen sensor B1 S2 malfunction : p0140

16541- 163
oxygen sensor B2 S2 malfunction : p0157

17843-035
secondary air pump short to ground

17829-035
secondary air injection solenoid short to ground

17833-035
evap purge valve short to ground

17923-035
intake manifold short to ground

17880-035
evap leak detection short to ground




I just finished replacing my front left front pipe and replaced the downstream left O2 sensor. Car is and 99 A4 2.8lQM 30v. Can anyone help me determine the problem here. I didn't mess or disconnect any wires other than the battery and o2 sensors for the left pipe during the repair. and i abbreviated the code output a bit just to shave some time of the typing. Used autel vag405 scanner not vcds.

 

it says

all 4 02 are bad - usualy not a good sign, probaly a wiring problem if you knwo you just replaced one. or you have an exhaust leak on both sides and they are both not reading right.

sai - both codes cause by bad pump

I think the intake mani ground is the one off the throttle body to the head. Not 100% sure

Did you clear the codes with the tool? Thats the important part. Then rescan and see what returns in 20 miles.

 

i do still have one exhaust leak where the left front pipe connects to the rear resonator pipe. I didn't have the right hardware to get a perfect seal, but since this is behind the sensors shouldn't it not effect them? and yes i did reset the codes and the light went out but i didn't drive it yet. Ill do a re-scan on it when i have the chance and driven it. But what concerns me is i had none of these errors prior to the repair. Excluding the o2 sensors the other errors appear to be electrical problems. Could it be so simple that i unplugged something by accident while in the engine bay?

 

Well, you would have to unplug a lot to get all the codes. Honestly I wouldn't worry about them until the rescan. Go drive for a bit tomorrow and get it scanned again. That exhaust leak wont cause any problems since its behind the sensors.

 

Honestly yes it could. Did you by chance turn the key on before everything was hooked up? The low terminal 30 voltage refers to terminal 30 on the ignition switch, meaning expected voltage wasn't seen there. It's usually a crap code. JBJ is right - drive the car with the codes cleared. Anything that comes back will need troubleshooting.

FYI, the operation of the secondary air pump is monitored by the secondary O2 sensors - if either is bad, it can cause the ECU to report fail codes for the other. Seeing that your codes show shorted pump power, it's more likely that the pump is the issue and is causing false O2 sensor codes, rather than the other way around. And just to put it out there for clarity, bank 1 is the passenger side and bank 2 is driver side.

 

thanks for the tips guys. Just as speculation at the moment but going off of what you were saying devil about the correlation between the o2 sensors and the SAP. When i replaced the O2 sensors i didn't go with a quality oem or bosch part but instead opted for a cheaper third party sensor. As pure speculation right now do you think the third party sensor it giving a bad reading therefor interfering with the SAP readings and causing it to say that now all of my O2 sensors are faulty? again just a thought ill get back tomorrow after i rescan the car.

 

Thats not possible but a good thought. The sai reads off the 02 and decides to inject air into the cats to up the levels of horse **** it needs to operate. You have both codes tho, flow and bad pump. Usually points to just a bad pump. I wouldn't be surprised if that code came back.Did you splice the 02 correctly? With generics you should have to splice them in.

 

alright i had a chance today to drive my car and basically all of them came back except low voltage at terminal 30. and to answer your question Jon the sensor came with the plug so i just had to plug it in no splicing required. but now since all of these codes are back you believe i am looking at having to replace my sap?
and should i be concerned with the other shorts with manifold and evap?

 

*bumb*
hey guys im hoping that i could get a little more help on this problem. I eventually gave up trying to fix this myself and brought it into a shop. The shop managed to fix the O2 sensor problems cause silly me didnt zip-tie the cables up good enough while reinstalling everything and they got caught up and ripped. But all the other codes shown above are still present. And i just stopped by the shop today and their starting to get frustrated by my car and they are unable to fix the codes and its been there for almost a week now. So im hoping someone can give me any help so that i can pass emisions and not get a ticket.

If anyone knows the wiring of these vehicles well that would be a huge help on trying to track down what is giving me these problems. additionally this is a long shot but could it be the ecu that is failing? could a IC in the ecu have fried and now the ecu continually thinks that these systems are bad? and second could it be possible to purchase a second ecu and reprogram it to ignore these codes. I know this sounds difficult but i have done computer programing before and built IC circuits so even its a long shot if its an option id like to pursue it.

 

SAI Pump is bad

Probably have a vacuum leak somewhere

intake manifold short may be the wire on the back of teh throttle body? not sure