You checked at the beginning of the ECU, or at the harness right next to the actual sensor?

Because those readings look about right..

Two between 0.1-1.3, one which is your power that's your 12, and the ground.

 

I checked at the harness right next to the o2 sensor...

I just got another maf today and I am getting the hose air intake and the hose air bypass replaced tomarrow or Thursday-whenever the parts come in. Found a little hole on both of them....but dont really know if this is whats setting the cel.
will keep ya updated

 

Okay guys, I replaced the maf, the air hose intake and one of the vacumm hoses, reset the ecu and STILL same codes p0135 and p0131.

Could the car be running lean??

If so what do I check? Fuel filter, fuel injecters??

Zoned019 the voltage for the o2 sensor seemed right?
What do I check for next?

I would take it to a mechanic but the first thing they say is that its the headers.
I know that people on here have the same setup as I do with no problems.

Could it just be the ecu itself.

ANY piece of advise or opinions would be helpful.....

 

I can't really help too much at the moment as I'm on bad internet...

go to hmaservice.com ... use the user name and password provided in the sticky in the new users forum.

Type in the code, and look at the steps to isolate the problem.


A MAF or TPS isn't going to cause an o2 sensor light... either the sensor is bad (you put in the wrong one), the wiring is bad (compare the results you got to those on hmaservice) or the ecu is bad.

 

Hey, I tried to use the search on hmaservice.com but nothing appears.
I cant type in the codes anywhere, can anyone post the step to step so I can isolate the problems

Or maybe Im not doing something right?

My codes are p0131 and p0135 on first sensor.

Trying to get this fixed......

 

I already pasted everything from webtech....

as hamhead said, either the sensor is bad, the wiring is bad, or the ECU is bad.

The chances that the ECU is bad are very slim, check your wiring again man....like I said, there's 2 signal wires which should oscilate between 0.1-0.3 volts, your power, and your ground. Touch the multimeter to that power and that ground and see what you get. First I would check for connectivity with the meter, if you get that, then check for voltage. Do this at the o2 sensor harness, and follow it back until you get a reading. If you get all the way back to the ECU, then I guess the ECU is bad, but you should be able to isolate the problem by following the wiring back, once you hit a spot that is GOOD, then you know all the wiring from there on is bad, so fix it.

and make sure to have the key in

 

Did you relocate your O2 sensor since you got your header. It dosn't work correctly unless it's after the Catalytic converter.

 

Okay I will do that.

I just checked all four wires at the end of the harness where the o2 sensor plug into.

This is where the o2 sensor plug int the harness that runs to the ecu.

Now, I checked the voltage on all four wires at the connector(where the o2 sensor plugs into) and I got the readings that I posted before.

So, now that I do have voltage at the harness, does this mean the wires could
still be bad somewhere going down to the ecu?

 

Are you connecting the ground wire to the multimeter, or grounding to the chassis? May be your ground that is bad, so when you test the power test it with the actual ground wire from the harness too..

Again, it's either the wiring, the ECU, or the sensor itself. The problem is right in front of you...

you could try just ripping out all the wiring from that sensor and redoing it ALL, from the ECU to the sensor.

Where are all our electrical gurus? This is not my dept..lol