Coyote
Member
My engine has been throwing this code since I put it back in the car. I got the same code about 2 years ago and replaced the O2 sensor. Never got the code again until now. When I first cranked the engine after having it out of the car there was quite a bit of smoke. This came from oil making its way into the exhaust manifolds while the engine was upside down on the stand. I thought maybe it was clogged with soot so I removed it and cleaned it up as best I could. I made sure that the openings in the "sheath" were open and free of carbon. Seemed to work for a while but then started throwing the code again. The only reason that I hesitate to replace the sensor again is because I had an identical problem with the OBDII in my 2000 4Runner throwing the same code! Changing out the O2 sensor didn't solve the code issue. Turned out to be a bug (yes a real bug!) on the MAF sensor. I'll never figure out how it got there since it is down stream of the air filter. I suspected that maybe something similar happened on the LT4 so I removed, inspected and cleaned the MAF sensor. It was a little bit dirty but cleaned up nicely. No bug! Still throwing the code though. Any ideas before I cough up some more money on a new O2 sensor? This also leads me to another question: Why not any of the other three O2 sensors? Car only has 56K miles.