If I am not mistaken, it's typically some (not all, and I don't recall which ones off the top of my head) of the aftermarket radio harnesses that interfere with flashing the PCM

BBEngineer

 

Wonderful! I am going to have to try this. We had been taking the PCM out of the car and flashing it with an offboard and reinstalling it. I might do the radio fuse just to be sure. We are using a PT so should be the same.

 

Im going to hijack
Im having a very similar issue with a 01ls monte with the 04 N/A 3.8 harness and ecu. I keep getting the 02 codes same as above and I check the plug and there is no voltage. The problem with this is that it misfires unless I set it with the programmer to run in open loop. How can you fix this?

 

sorry to bump such an old thread , my 04 mc ss sc has been having the p0134 and p0135 for a while , so i replaced the wire from the rear of the engine to the sensor with a new one and replaced the 02 with a new denso , same thing codes pop up . Now someone on another site , i don't even know if it was a gm car said check the 02 sensor fuses . Do we have 02 sensor fuses ?

I gotta get this inspected by the end of the month and don't know what to do .

mods 3.6
open cone
180 stat
ssac headers
zzp mail order tune

aeroforce to monitor things.

 

Are you 100% sure the replacement sensor is heated?