'DTC P0158 H02S Circuit High Voltage Bank 2 Sensor 2' Noticed a check engine light and got a P0158 from the Odometer- anybody know what this is... computer codes and stuff is all chinese to me- appreciate any input!! Thanks!

*Figured it was the O2 sensor. For some reason I only have 1. Checked the whole exhaust system over in the rain, and only have one, right on the y-pipe where it becomes one. There never was one behind the big cat, and there's nothing there now... nor is there any cut wires or anything resembling a simm. WTF? Is it gonna be not such a good idea to drive this thing like this? I need to be able o drive it about 100 miles everyday... Thanks!

 

HMMMMMMMMMMMMM, I have no idea, I HATE computers and wires. you should probably have 2 02 sensors, can you see any wires hanging by the rear of the tranny

 

There should be one it the pipe after the Cat, thats OBD II spec. By your sig I looks like it was all chopped off and straight piped. Maybe somebodycut off the connectoror tucked it out of the way.
Is this truck new to you? I would think the MIL would have come on long ago if this was the case.

 

I just checked, and I do have 2, but they are right after the little cat-things on the downpipes. Then it Ys into one pipe, and theres the big cat, and there never was an 02 behind that... I've had the truck for ~30K and it just finally threw the 02 sensor code, bank 2.... anybody know what side that is so I can just replace the faulty one??? Thanks for the replies..

 

I got the code a few weeks ago when the truck was idleing in the driveway, I took the truck to autozone and used the scanner there to erase the code and it never came back... I would try that... maybe its just a fluke.

 

yeah... I erased the code by unhooking the battery, and then just put ~35 miles on it, and it didn't come back, I figured out it was the passenger side one... so II'm gonna replace it and see if that helps anything else (e.g. hard starts and rough idle)... We'll see... Thanks for the replies.

 

OK, just noticed your in California.
Therefore you should have 2 cat converters (one on each pipe from the engine) and 4 O2 sensors.
I think bank 2 sensor 2 is on the passenger side after the converter. Not 100% on which side but sensor 2 is definitely post Cat.

 

Bank 2 is the right side.......

 

O2 sensors don't affect hard starts or cold idle. The PCM doesn't read info from the pre-CAT O2 sensors until the engine reaches operating temperature and exits closed loop operation. The fuel mixture is high on cold idle warmup to heat up the engine quicker, and the O2 sensor would tell the PCM to lean out the mixture, causing a longer warmup period.

 

It's true it wont effect a cold start but these (OBD II) with heated O2 sensors can go into closed loop in under a minute. So well before your fully warmed up your O2 is trimming fuel.