Thread: P0135 - replace o2 sensor?

I'm not sure if it's related but I went from a 3.4 pulley to a 3.6 and a week later I'm throwing a P0135 code: Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1). I also have a slight exhaust leak in my headers (have had that for awhile now). When scanning at idle the o2 is reading around 800 and if I get on the gas it's 930+. This would lead me to believe that the sensor is working if it can get readings. Car has 84k miles.

1) Do you think my front o2 is actually bad or could it be something else?

2) If I do replace the o2, what brand should I get? AC Delco, Bosch, Denso?

Thanks

Fix your exhaust leak, and check the o2 wires... make sure they aren't melted or boogered up.

i get that code all the time, its a brand new 02 sensor on my pacesetters. IMO the headers are causing a false code.

o2 wires are fine. It's now throwing a P0030 code as well. Ordered a Denso sensor from autozone, will be putting it in tonight. Car has 84k miles so it's not a bad thing to change it now anyways even if it is still good. Been getting super ****ty gas mileage the past few months too....

Originally Posted by 99prixgt

i get that code all the time, its a brand new 02 sensor on my pacesetters. IMO the headers are causing a false code.

Must be. I fixed my exhaust leak, looked over all the wiring, and replaced the front o2 with a brand new denso. Cleared the code but it's still coming back. I tried searching the various forums for posts on this code and wasn't able to find much information. I would think there would be many more posts on this if it really was caused by the headers. I'm not sure where to go from here. Suggestions anyone?

TTT
still having problems

is there any way to simply put in a new o2 bung further down the pipe maybe? and just bolt off the first bung

I dont even think dirtmaster posts here anymore,

heating circuit means you need a new O2 sensor or the wiring needs to be checked.

Today was the first really cold morning I had to drive my car and for the first time since I can remember I did not have a check engine light on my 15 min drive to work. It seems like this code is only present during warmer weather, or maybe just a coincidence? Either way, I'm going to have that code deleted out of my PCM on Monday so I won't have to deal with it again.

I think it's safe to say that the headers are causing the code. Not that you still shouldn't look at the fuse/wiring/o2 sensor though.