https://www.automedicsupply.com/cata...01c6f2626ea243

$126 OEM
$51.90 aftermarket

 

^would you need the downstream one..not the coldstart one

 

you would need the one that bolts to the exhaust manifold. the one in front of the cat would just cause a cat efficiency code or somethin. the one in the manifold is the one used for air/fuel ratio.

 

You need a new O2 sensor. Your current O2 sensor is sending false readings to your ecu right now. There is not much correction from the ecu. With the A/F guage, you should be sweeping lean to rich unless you just started your car which will give you a rich reading until the O2 sensor heats up, then you will sweep. When you don't have any exhaust running through your pipes, you shouldn't get a reading or a very low reading. When you punch the gas with the A/F guage you should get a slightly rich reading. I would try replacing the O2 sensor. That should help.

 

damn i might go order a new O2 sensor then...cus i thought my gas mileage was normal

 

replace the upstream O2 sensor and see if your gauge reading is better. I would doubt that your downstream sensor is bad yet. It catches all the cleaner exhaust. However it is possible that they are both bad. the upstream has more input to the a/f mixture and also is where the gauge is hooked up to anyhow. see if your readings and mileage get better. I would do that before taking a more expensive route.

 

wow. bad o2 sensors already. i'm at 103k on the stock sensor and still getting 30-34 at most nowadays. mine might be on it's way out, but it's lasted quite a while.

 

There are alot of things that can cause a sensor to underlive its life expectancy.

 

^ya i guess..cus im averaging 22mpg on shiaty cali gas...

 

yeah, i know. just sucks to hear it happen.

 

I reset the ECU and moved the signal tap from the o2 sensor wire in the engine bay (before the harness, on the unshielded wire) to the wire that goes into the ECU. It's giving me the sweeping reading all u guys are talking about now. It's 100% rich when i put the pedal past 75% throttle, while cruising with minimal gas it does about 2 full sweeps (lean to rich and back) in about a second. then when no gas coasting to a stop its either 100% lean or the gauge isnt even on. When I start my car from a cold start it reads 100% lean but then when i start going it starts sweeping.

But my guess is my mileage is gonna be exactly the same since all i did is moved a wire and reset the ECU.

 

This will not help if the sensor is bad.

 

No duh

If u read closely I said that my gauge is reading correctly now which means the sensor is ok, it was just a bad connection.

 

Sorry, I was reading it as if you still had problems and were unaware of them. Replace the upstream sensor and see if it doesn't fix both problems.

 

is it pin 76 near ecu? I have mine in the engine bay right now. Also how did u tap into that wire?