I've done some searching of this forum for related problems people been having, and have posted some questions on various theads, but so far I haven't drawn out my whole story on the SES codes I've been having.

I thought I'd post my own story and maybe help out some others who may be having the same problem, as well as getting help myself!

Here's the full, complete, unabridged version...

Back in December 04 I had SLP LT's installed my my Z28. The installers fabricated their own O2 extensions, and used my stock O2 sensors. After the install, my SES light kept coming on for the following codes:

P0135: O2S Heater Curcuit, Bank 1 Sensor 1, Malfunction

P0137: O2S Circuit, Bank1 Sensor 2, low voltage

P0155: O2S Heater Circuit Malfunction (Bank 2 Sensor 1)

P0157: O2 Circuit Low Voltage (Bank 2 Sensor 2)

The I-pipe and Y-pipe were also banging horribly against the floor pan, so I took it back to the shop that installed them and asked them to fix it.

So, they loosened the header bolts, re-adjusted the Y-pipe, re-tightened the header bolts and then tightened all the clamps down on the piping.

Started it up... backfiring! Turns out the rear-most part of the passenger header wasn't seated all the way down, as you could see fire coming from the exhaust port!! So they re-loosened the passenger header, and re-tightened it back down. Fired the car up... everything seemed A-OK.

I asked them about the DTC codes coming up, and they said there wasn't much they could do about it because they didn't have any PCM editing software. They said to just keep clearing it on my Predator, that it should only be temporary, and if it comes back to let them know.

Well, after a few days of driving around, another DTC code started showing up: (in addition to the four codes listed above)

P1153: Heated Oxygen Sensor (HO2S) insufficient switching bank 2 sensor 1

By now, I've heard about the wonders of the Bosch #13111 rear Corvette O2 sensors, and how they seemed to fix alot of problems O2 related with a header install.

I went to an exhaust shop and had them re-work my exhaust, because even after re-adjusting the headers that second time, there was still banging on the floor (although not as much... still, banging is banging, which is ANNOYING). The exhaust shop fixed all my banging problems, piece of cake.

While my car was in the exhaust shop getting worked on, I walked to the local parts store and picked up some of the 13111 sensors, and while my car was up on the lift at the exhaust shop, I had them install the sensors for me.

Got my car back... cleared all the DTC codes, and took it for a spin. So far (knock on wood), the only code that still keeps popping up is:

P1153: Heated Oxygen Sensor (HO2S) insufficient switching bank 2 sensor 1

So, this is where I'm at right now. I've been looking for exhaust leaks on the passenger side, but so far haven't been able to hear anything. I also haven't noticed any unusual soot deposits anywhere. (although that doesn't mean there isn't a leak somewhere I haven't seen yet)

I'm going to have my car scanned today hopefully, and see if the PCM's history has anything to tell. I'm just going to drive around until the SES light pops up, then swing over to the shop and get scanned. Maybe they could tell me what's going on on that side.

But, if it isn't an exhaust leak, what would make the B2S1 throw P1153 and not B1S1?

If it's because the O2's or the exhaust gases aren't heating up fast enough, why would the drivers side be OK, and not the passenger side? And if this is infact the case, and not a leak somewhere... would header wrap take care of this, or at least help?

 

Are you saying you installed the Corvette O2 sensors in the pre-cat or the post-cat position.... not clear from your description??? I also didn't see (or possibly missed) what you did about the poor quality "extensions".

"insufficient switching" is generally a sign of contmination. Perhaps the seriously leaking header did some damage to the sensors, not to mention the possibility of having burned some valves.

 

The Vette sensors are in the pre-cat position. They don't require extensions because the wires are about 24" long or so, so it eliminates the need for extensions all together. And the heater on the rear Vette sensors is supposed to be better because it heats up faster... it has a higher wattage rating than F-body front O2 sensors.

And I installed the Vette sensors after I started getting the P1153, about 2 weeks after, to be exact.

The car runs just fine... I haven't noticed any performance decreases, it's just it's throwing that code, which really bothers me.

I'm almost positive this issue can be fixed, if I can positivetly identify what's causing it. Some people say they just live with the code popping up, others say they just delete the code using LS1Edit. To me, that's just a band-aid fix.

I just wanna nip this thing in the butt, and do it properly...

UPDATE:


Well, now I got both sensors tripping codes. Just checked it a few days ago with the Predator and the following codes pop up:

P1153: Heated Oxygen Sensor (HO2S) insufficient switching bank 2 sensor 1

P1133: Heated Oxygen Sensor (HO2S) insufficient switching bank 1 sensor 1


Got the car scanned... nothing seemed out of the ordinary. Apparently the O2's were switching like they should... bouncing from low 80 mV up to 800-900 mV sometimes.

When I look at it myself with the Predator, yes, sometimes it seems a little "lazy", as in it doesn't always switch between high and low fast enough. I'm no expert or anything, but it seems to me that *sometimes* they work, and sometimes they don't.

So far, these are all the suggestions I've got on what to do about it:

1) Delete the codes out of the PCM - To me, that sounds more like a band-aid than a fix. Sure, it'll keep the SES light from popping up, but the PCM will still read the O2's as not switching properly.

2) Use header wrap to warm up the exhaust gases - I called Thunder Racing and asked them about this suggestion and they said that may not be a good idea, considering my headers were already coated. The excessive heat held in from the wraps might bake the coating and eventually warp the metals used in the headers due to heat stress.

3) Check for leaks - I've looked for leaks, and had a few other people look for leaks as well, but so far we haven't found anything

4) Get new O2 sensors - Some people rave about the Denso sensors being the "best", while some have had unsucessful results with them. I guess all brands of O2 sensors are a "hit and miss" in this situation. Maybe I'll try another brand next time I swap O2's with something other than the Bosch 13111 I currently have installed in the pre-cat positions.

5) Burnt wires - That's a negative there. No burnt wires from what I can see.

5) Check the wiring - I may have dirty connectors, or maybe there is a short somewhere. To be honest, I haven't investigated this yet.

I also read in a few places about if you have coated headers, and they're brand new, that sometimes the coating inside the headers bakes off and can screw with your O2 sensors. SLP LT's are coated, so I'm really hoping this is the case for me, because all I have to do ride it out. But knowing my luck, things won't be so easy!

Ah well... the quest continues...

Please, anybody chime in if you have any inputs...