I have a 2003 Silverado Z71 5.3L with 58k miles on it.

My check engine light came on about 200 miles after I installed the Volant Air Intake. And it was throwing code P0135.

This code refers to the front oxygen sensor on Bank 1. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0135.

So a few weeks ago, I replaced the 02 sensor in bank 1 sensor 1, and cleared the code. Only to have it return the next day. So today, I took the Volant out and put the stock air intake back in. But I still have the code. I am at the point where I have to take it to a shop soon if I can't figure it out because I have to get it smogged in CA before I move to IN on wednesday morning. any advice? thanks.

 

I would check the wiring going to that sensor. Also a cause could be a catalytic converter going bad on that side. I don't think the air intake has anything to do with it.

 

i just went to a shop and he said my 02 sensor is dead. so i'm going to replace it again and see if it works out. i'll also check the wiring going to the sensor. i wouldn't think my cat would be bad with as few miles as the truck has....but the sensor also shouldn't be going out this soon either so who knows. i agree, i don't think the intake had anything to do with it, but i was just canceling out some possible causes and the light came on right after i installed it, so it made sense to me.