Runnerfan

I have been getting a P0125 since I got my new exhaust done. The exhaust was new from the y back with 2.5", high flow cat, magnaflow muff. Got the P0125 after, so I had mechanic check it out and the front o2 sensor had no voltage output. So I changed the o2 sensor but the CEL is still coming on. The readings on the OBD II freeze frame data are always different. When it was coming on before the new o2 sensor it was always the same (STFT 0%, LTFT 11-14%, 35-40 mph, 16-1900 rpm) this is cruising in 5th gear. If someone could please give me stock measurements:

from crossover/y collector flange -TO- the first o2 sensor
from first o2 sensor -TO- front of cat
from back of cat -TO- second o2 sensor

Does it matter if o2 sensors are mounted vertical or horizantal?

And the motor is from a 96 m/t.

Runnerfan

Could I be getting this code because I hooked my fuel pump relay right to the ignition instead of the wire coming from the ECM. I have the FSM for the P0125 and all it shows in the circut is the EFI relay(powers the o2 sensors) controled by the ignition switch, and the o2 sensors giong to the computer. This is why I am thinking that it may be the location of the sensor.

Could someone please help it is only a few measurements. I don't want to get caught taking measurements under some random persons 4Runner.

Runnerfan

Ok I am a idot! I solved the P0125, turns out I had the shielding ground hooked up to my sensor when I extended my o2 sensor wires. I hooked up the right wire and no more P0125. I thought my CEL days were over until I was sitting at an idle and the stupid light came back on. I checked the code now I got a P0171, so I cleaned the MAF last night. Sow now the question is could I be getting this code because my front o2 sensor is about 2 feet from the crossover flange? I found a picture on here that looks like the sensor is only about 1 foot from the flange.

Runnerfan

The p0171 keeps coming back. The code comes on after I have been sitting at an idle for a while with the engine having been at full temp for about 10 min. I will post the freeze frame info from the obdII even though no one is trying to help. Just talking to myself here.

Fuel Sys 1: CL
Calc Load(%): 9.4
ECT (F*): 192
STFT(%): 8.5
LTFT(%): 21.8
RPM: 878
IAT(F*): 91
MPH: 0

Any ideas, please.

dntsdad

I'll measure my distance for you. Mine is 100% stock.

dntsdad

Looks like 12" from the downpipe flange to the first sensor. 7" from the rear of the CAT flange to the second O2 sensor. Total distance between the two is 28".

Good Luck

Jason

dntsdad

Here is the page from the manual.

http://ww2.justanswer.com/uploads/sk..._99_runner.pdf

I believe that P0125 code can also come from a faulty or stuck thermostat, insufficient coolant, etc.

I would change the thermostat and top off the coolant if that code is still present.

For the P0171, usually a good cleaning of the MAF will fix it. Also, check for vacuum leaks with some starter fluid or something similar. I would hit the MAF again.

You are resetting the ECM with a OBD2 tool, or disconnecting the battery for about 10 minutes or so, right?

Runnerfan

Wow a response, thanks! I have checked for vacuum leaks a couple of times. I reset the ECM both ways. The P0125 is gone, now I am just working on the P0171. I also have a second MAF that I will put in and see if that stops it. I am worried that I may have a exhaust leak in my crosover since I cut up the original and reused it(may have a bad weld). Man that would suck to have to get at that again. Could having the o2 sensor hooked up to a ground cause it to now be faulty?

Runnerfan

I don't want to be difficult but I am also wondering what the disstance is from the first
o2 sensor to the cat element/filling(not sure what to call it, maybe guts). Because I have a aftermarket high flow cat. Also from the "guts" of the cat to the second o2 sensor. I don't want to get the sensors to close to or far from the cat and get the wrong readings. I just want to get it right the first time, well I guess this is the second time.

dntsdad

I am not sure that an exhaust leak could cause the code. Hopefully someone smarter than me will respond.

Not sure on the O2 sensor either. I would try to find something to show/see if it can be tested. I would assume so but I have never had to mess with them so I really have no idea on that either.

Not a lot of help on the above but here are the measurements that you wanted, including the other one from the front O2 to the CAT "guts".

Jason

Runnerfan

Perfect picture, thank you. A little more info on the front o2 sensor wire: I hade the white wire(OX1) hooked up to the shielding gound wire instead of the white wire inside the shielding. Could this through the sensor reading off? Would a lean code be caused by the heated circut(HT1) of the o2 sensor or the OX1 circut?

dntsdad

Personally I have no clue so I really cannot help. Sorry. I have no expertise in that.

Hopefully someone else can, or maybe post up in the taco forum here or at Ttora.com

Good luck