OrthoAggie

While driving today my check engine light came on and I luckily just installed my Carchip scanner the day before to read codes and other readings...the following codes seem to appear every time the car is started:

P0157 O2 Sensor Circuit Low Voltage (Bank 2, Sensor 2)
P0300 Random/Multiple Cylinder Misfier Detected
P1416 Unknown Powertrain DTC (Manufacturer Controled, Auxiliery Emission Cont

and then this code came up twice, once while the car was in motion and then the next time the car was started: P0134 O2 Circuit No Activity Detected (Bank 1, Sensor 1)

now since each code is coming up every time the car is started, is this something that happened previously and is being stored in the computer? Each misfire code has the same information for engine speed, load, and vehicle speed, which I am assuming is what happened when it first threw the code and it just keeps repeating the infomation everytime the car is started.


Well what should I do first? I dont have the service manuals yet...i bought some from a forum member and should have them in a day or two...so what would you guys do first? Thanks

Mo_Bandy

hey there,

Well there could be a couple things happening....

1. it could just be a bad O2 sensor and it is causing the right back to run lean causing the misfires....

That would be the first thing to check.

Second but probably less chance is that your catalytic converter is plugged causing the O2 to read strange.

What year is your car?

Mo

OrthoAggie

car is a 96 LT1 with 83k and i recently replaced both O2 sensors before the cats about 6 months ago, but not the ones after the cat...the Bank 1 O2 Sensor 1 is the code that actually made the light come on also

OrthoAggie

ok i reset the check engine light with the chip and took the car out twice restarting it a few times and no codes came up...i am assuming the previous 3 repeating codes was from a previous event since they are not come up anymore

Mo_Bandy

thanks ! uhm I would first check the connection, hopefully they put the wires out of the way of the exhaust. you may luck out to find that it is just unplugged....

Mo

OrthoAggie

i know it is working...i plotted the O2 sensor voltage and could see when it stoped reading and then it started to pick up again so i think there is a short in the sensor...about 12 minutes into my trip the voltage dropped to 0.1 volts and never went about 0.4 volts while the other sensor was peaking at 0.9 volts. That sensor keep showing this behavior for about 20 min and then came back to normal. The code came up after the sensor was doing this for about 4 min that the sensor started to read very low...i think that it is just a short in the sensor and will just replace it and see what happens...any other opinions?

OrthoAggie

Bank 1 O2 Sensor 1

Bank 2 O2 Sensor 1


you can see where it started to malfunction

http://www.sounddomain.com/memberpage/479196/7

go there to see pics until corvette forum approves them