Repeat HO2 sensor failure

[Alexander]

Hi everyone,

I have a 2001 Suzuki Swift (you may know it as a Geo Metro), it’s running the G10A engine (993cc), and has a bit of a gremlin.

The car arrived with the P0134 code, low and behold the original sensor was dead. So I replaced the sensor, and found the replacement to be giving a 0.97-1.01v output. Naturally, the part went back for warranty replacement, and I recieved another sensor, plugged it in, and guess what. Same issue.

I do have a small amount of white smoke (the car hasn’t moved in 6 weeks, though the engine has been turned over for diagnostics), this smoke doesn’t clear up when the engine is warm, and I’m still getting the same error code. There are no other codes being registered along with this, and I can’t see any other malfunctions on my reader (which doesn’t give me live data).

Do any of you have experience with such faults? Where do I go from here? I’m beginning to think it may be the ECM at fault, but have no idea where to find a replacement, any ideas at all folks?

Topic

[Its me]

You really need to put it on a scanner with live data to figure out this problem… If you do this, copy/photo it and post here and we may be able to help… Also, Show us the Freeze frame data for that DTC and any pending DTC’s…

For a simpler start, while it sounds weird, I have found issues with the MAP sensor causing O2 codes like yours… (ensure your MAP is hooked up and all vacuum lines are good with no leaks)…

-Karl

[Bill]

I don’t know how you determined that the original O2 was dead but if the long term fuel trims were maxed either way you might need to do a complete reset of the PCM. Disconnect the battery terminals and connect the cables together for 15 min. Reconnect them and test the O2 voltage.

[Alexander]

Thanks guys. The original sensor didn’t provide a voltage at all (it may have been in the car for 70k miles).

The battery has been disconnected a few times, the longest period was for 2 weeks while I welded up a couple of holes on the driver side sill. All I have is a cheap OBDII reader to grab and erase codes with, and a multimeter. On a timeline scale, I serviced it prior to an MOT, it failed it’s MOT back in the 2nd week of January. I Took the car home, and did an initial diagnostic flow. Didn’t find any other faults (no air leaks, SPI creates fine mist that is difficult to see, not dripping, no fuses blown, no exhaust leaks, no blocked vacuum hoses). Checked the spark plugs (brand new, gapped to suzuki specs), they came out black. Replaced the distributor and rotor, re-gapped to NGK specs, tested. Re-gapped to Suzuki specs and ordered the first HO2S. I then began welding while the new sensor arrived. After arrival, I re-connected the battery post-fitting, ran the car through 6 driving cycles, clearing the code that popped up every 2 cycles. I then got the multimeter out, found no shorts on the loom, but the sensor was throwing out 0.97-1.01v, so I sent it back. Finished the welding, received the 2nd new sensor and repeated the process again.

I’ll try and source a reader with live data, but if another sensor was to fault, would it not give a code for that sensor too? How likely is it to be a faulty ECM?

[Its me]

I am not so sure it is a faulty ECU…. It could be, but that is the last thing… Since it is throwing codes, I am not so inclined….

If the MAP is out of line, it may, or may not throw a code… This is not the likely problem, but I just want you to be aware something this simple can throw everything out of whack…

The live data for open loop and closed loop may help us…. That is the best clue we have for why a rich condition may be occuring and really maxing out the O2 sensor.

I had a Toyota that was doing this to me and I found out that it was losing too much vacuum through the 4WD actuator and that was effecting the MAP sensor… Throwing everything off and giving me the same code you had…

I pinched off the vacuum line to that 4WD actuator and it brought everything back in line… It was only through live data that I saw the MAP sensor was getting really unusual vacuum…

Best of luck…

-Karl

[warren kruger]

Welding?….what type of welding?

[Alexander]

Welding on the sill, had a couple of small holes that needed sorting out.

[Author]

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