just bought an 01 ss and it had a check eng light it was the 02 sensors on the driver side replaced both and now it says all 4 02s are bad! hit a hard bump and the light shut of and now it just came back on any ideas!

 

make sure there all tight....any leak of unmetered air will set them off....if the fronts were bad the car would run bad

 

any other things I should look for

 

Both 02 sensors on the drivers side were bad at the same time? What code(s) are you throwing now?

 

dont remember but I got is scand again today and the code was p0154 thanks for any help!

 

sticky could tell u....but ill check for u....hold on

 

P0154 02 Sensor Circuit No Activity Detected (Bank 2 Sensor 1)

are you sure the cars not running funny? might want to check that o2s fiting

 

cars runs funny and has a bad exhaust smell ! will this mess up anything else ?

 

id have to say that o2 is leaking or messed up....resulting in running rich and bogging, it wont really hurt your car but you need to get it taken care of, it will ruiin your plugs, cats, and o2s....

 

Hai,
The 02 sensor is right at the entrance of the tube that the open air filter connects to...some say that open air cone filter sucks in too much for the 02 sensor to handle causing the failure...

That's not the Oxygen (O2) sensor, that is the Mass Air Flow (MAF) meter. The oxygen sensors are located in the exhaust manifolds and in the exhaust pipes just downstream of the front catalytic converters (total of 4 O2 sensors).

Anyway, there is no way an air filter change is going to affect the O2 sensors. There is a slim possibility that an oiled type air filter could contaminate the heated wires in the MAF, but this is a very remote possibility. If that is the case, the MAF can be cleaned with some spray type carb cleaner.

The main problem I see with these aftermarket airfilter assemblies that replace the stock airbox is that they don't exactly match the cross sectional area of the pipe where the MAF sensor mounts. The air inlet tube is about 3" in diameter except where the MAF sensor is mounted and there it is compressed about 3/4" at the top where the sensor bolts on. The MAF sensor just measures air temperature and air velocity and then the computer calculates the mass of air flowing into the engine based on the cross sectional area of the pipe at that point where velocity is measured. If you go and enlarge this pipe at that point, the computer has no way of knowing that and will calculate mass air flow based on the smaller pipe when in reality you will likely have more air flowing past the sensor than previously. This could result in a lean condition until the computer remaps the fuel curves (using input from the oxygen sensors) for a given throttle position (assuming it has the capability to compenstate for that amount of increased air flow). This remapping evolution takes some time though. This is one reason it is a good idea to reset the ECU during mods like this (just disconnect a batter terminal for 30 minutes or so) which resets the fuel curves back to default values which are typically richer than normal. These richer fuel values allow the truck to continue to run without damage in the event of an oxygen sensor or other sensor failure. Once the ECU is reset, it will begin to "re-learn" the optimum fuel settings based on new input from the available sensors.

 

What are you talking about, no one brought up air filters?

If you hit a bump and get an 02 code, check your ground wires. The PCM wiring harness has 3 grounds on the back of the drivers side head.

 

thanks for the info guys ! so I should just make sure their all th e 02s are tight and the pcm grounds are tight behind the driver side head! anything else?

 

There are some fuses that have to do with the o2 sensors. Double check all of them in the fuseboxes under the hood, as I can't remember which one(s) to tell you.