176 code after new sensors

[wht93atx]

I was getting a check engine light that was increasingly coming on more often, When I checked the codes it gave me 176(a few other, but I forgot) I replaced both o2 sensors, and it was working fine for about 40 miles on the way to work I had the ce light come on, I just checked the koeo codes(haven't had time to do the koer) and I get 176 again, I unplugged the battery for about 10 seconds, so I'm sure that it reset the code. any reason why one side would be running bad, I'll get some pics of my old o2 sensor up one had soot on it and the other was a nice clean gray
THanks

 

[sdpatt]

Unplugging the battery for ten seconds will not erase the codes. You must install the jumper, turn on the key and remove the jumper after the codes start being displayed. Until you confirm that you have cleared the memory codes, those "few other" codes that you forgot may be a key clue as to the problem. Clear the codes and run the test again after the CE light comes on again. Write down all of the codes. Let us know what you find.

 

[wht93atx]

K i reset the codes and I'll still get a 176. KOER codes are 111 and cylinder code is '9' Any thoughts. my milage is worse than when I got it(about 17-18) used to be 20-21

 

[rangerj]

wht93atx,

The 176 code indicates the front O2 sensor is telling the computer the mixture is lean. You assumed that the problem was the O-2 sensor.

It could be a vacuum leak causing the lean condition. Clear the codes and see if the lean indication comes back. If it does, check for a vacuum leak.

As SDPatt has posted numerous times, "don't throw money at a problem before you do the diagnostics" (paraphrased).

Please keep in mind that a "code" will tell you which sensor is involved in the problem. The code does not mean that the sensor is the problem.

The problem could be the connection, say due to corrosion, a shorted or open wire relative to the sensor, or in the case of the O-2 sensor a lean condition due to a vacuum leak. If this is the case, then the sensor is working properly.

Lastly, it is still possible that your new sensor is faulty. Do some more diagnostics and narrow down the possibilities. rangerj

 

[wht93atx]

I did reset the codes and the 176 came back up. any idea how/where I'd start searching for a vacuum leak? Just puzzles me that when i replaced the o2 sensor it was good for about 40 miles than the light started coming on agian.

 

[wht93atx]

anyone?

 

[twr]

Did you verify that the codes were cleared by running the tests again right after clearing them?? If are still getting the code without running the engine you have not cleared them properly.

 

[rangerj]

wht93atx,

Look at any and all vacuum hoses. Look at the connection for any splits or cracks. Feel the vacuum hoses and see if they are soft and plyable, or hard and cracked. Bend the hoses. Do they crack? If so replace the section of vacuum hose.

Next, with the KOER spray a carburator cleaner, like Gumout, along the mating surface at the intake manifold and the cylinder head. If the spray gets sucked in it is a vacuum leak at that point.

Check you snorkle tube from the airbox to the throttle body for any splits or open cracks. Check the 14mm rubber hose that runs from the center of the valley to the throttle body. It is the crankcase vent. This hose can get very hard and crack.

Look for any vacuum hoses that are not connected.

Hope this helps, Anybody! rangerj

 

[wht93atx]

Thanks will try and check the hoses this weekend.