1999 legacy l 2.2 auto cel check engine light o2 sensor replacement

[corlon]

had the cel come on. po135. bank 1 sensor 1 o2 sensor code. replaced sensor with new denso sensor. cel came back on after reset. any suggestions on what to look for next? anyone else experience same or similar issue?

[johnegg]

Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)

 

Causes

A code P0135 may mean that one or more of the following has happened:

O2 Heater element resistance is high

Internal short or open in the heater element

O2 heater circuit wiring high resistance

open or short to ground in the wiring harness

 

Read more at: http://www.obd-codes.com/p0135

Copyright © OBD-Codes.com

 

when the description uses the word ''circuit'', it is usually a wiring or connector problem.

 

follow the wiring back from the sensor as far as you can.

 

is the wire rubbing on the axle?

do you have a mouse problem, chewing on wires.?

wear spots?

water logged, salt corroded connector?

[corlon]

I did have some home insulation under my intake manifold. maybe a mouse issue. i'll start checking the wiring. thanks.

[spooln30]

I've had tons of Circuit Malfunction o2 cels that were bad o2 sensors. Not saying it couldn't be in the wiring or connection.

I'd bet he replaced the wrong o2 sensor?

Op which sensor did you replace? B1 S1 is tucked up and is in front of the first converter.

[spooln30]

Btw isn't there three o2 sensors on our cars? I just looked up a front converter on Napa and it shows there being two o2 sensor bungs so that would make three total right? It's been a while since I looked closely under mine.

[johnegg]

i know of no suabru 95 - 99 that has three o2 sensors.

 

i am not familiar with the SVX or the WRX so they could be different.

but legos and imprezas have only two.

 

some / all? third gens have more than two.

[corlon]

had a buddies shop do it. I called back after the cel came on. his tech said bank 1 sensor 1 because that's the cel it gave him. so theres one in front of the cat and one behind the cat? so if he says he did the front one then I should start thinking not the sensor?

[Headtrauma89]

I chased a p0130 (02 sensor curcuit malfunction) down for months, I checked the wiring, cleaned the plug, checked for vacuum and exhaust leaks, finally replaced the sensor and still didn't fix it.

One night I had a dream that I replaced the fuel filter and it fixed it. The next day I replaced the $20 fuel filter and within minutes, the light went away. A year later I still haven't had any more issues.

It was running lean (because of the clogged filter) and the sensor was telling the ECU to send more fuel. The ECU was responding by trying to send more, then the sensor still was reading lean. So naturally, the ECU thought there was something wrong with the sensor, and BAM, CEL.

[spooln30]

I just thought there were three becauce of the pic of the front converter on Napa Auto Parts website. They show it having two on the front cat, one in front and one behind. Then the one in front of the rear converter. Op, with a scan tool hooked up and on data what is the o2 sensors doing? The voltage readout should fluctuate from low to high volts at idle. Then flatten out when throttle is applied.

[spooln30]

Head, did your ECU set a b1 and b2 lean condition code? Normally when an engine is running lean or rich it will throw a cel as such.

[spooln30]

so if he says he did the front one then I should start thinking not the sensor?

 

I would unplug the front o2 and check if your getting all of the correct signals to the o2 sensor from the engine harness, if not trace backwards until you find them. If you do then plug it back in and with the engine running probe for signals coming out of the o2 but if you have access to a scan tool with data readouts you could check the o2 outputs on the scan tool.

[corlon]

o.k. talked with a local suby guy about my po135 code and that I already replaced the o2 sensor. he suggested replacing it again and that he has seen a lot of bad (or out of tolerance) o2 sensors. so I replaced it with another new denso o2 sensor. po135 code came right back? I have a scan tool that reads live data and is reading the front o2 just fine. should I be thinking an air/fuel issue ahead of the sensor? maybe an injector?

[johnegg]

check the wiring / connector to the o2 sensor.

[corlon]

filter looks good. probably replaced it 8 months ago or so. wiring looks good, but have yet to meter the connections. I have pics of the filter and live data of the o2 readings I will load later.

[twisty]

I have a scan tool that reads live data and is reading the front o2 just fine.

 

is the tool reading the voltage? the resistance also needs to bein spec, nt just the voltage reading.

 

check the wiring / connector to the o2 sensor.

 

this. if you can see voltage at the scan tool and the code comes back quickly, id check the wires/ pins at the harness, and trace back a ways to see if there is a wear spot, ground out or cracks in the wires that could be leaking/ shorting out intermittently

[corlon]

the tool is just reading voltage. do you know the specs for a resistance check? I would say the check engine light pops on very soon after a 2 key cycle.

heres pics of the air filter, po135 code and a snap shot of live data for the o2s.

 

http://i677.photobucket.com/albums/vv133/corlon/20140619_153343_zps7b01bb1f.jpg

 

http://i677.photobucket.com/albums/vv133/corlon/20140619_153535_zpsb2357d31.jpg

 

http://i677.photobucket.com/albums/vv133/corlon/20140619_153619_zpsa10c34a1.jpg

[corlon]

I think I won. downloaded the service manual for the car, printed off ecm and o2 pin outs and headed out to end a check engine light. 1st spot I start to look is the plug where the o2 sensor plugs into the car. cut the loom back and found the pin for the red/yellow wire to be 1/2 way out of the connector. looks like the lock is broken, so I just taped it to the wire next to it until I can hit-up a junkyard for a replacement plug. 5 key cycles and a test drive and no check engine light yet. thanks for your help on this one guys.