Correct O2 sensors

[daves8]

My check engine light has come on and off periodically in my L77.

Consulting with my tuner he advised the O2 sensors need replacing and that only the front 2 where active.

I have DPE headers, and wondered if anyone had a link to the correct ones?

Do I need standard length, or longer ones with DPE headers?

Are some brands better than others?

Thanks

 

[greenacc]

Bosch were factory fitted to VEs. I've never checked a VF but I expect they will also be Bosch. That's what I would be using.

 

[dassaur]

If you have DPE headers, why are the back 2 in use? Presumably they would have had all codes removed?

I just replaced my front 2x with NTKs and they are doing well.

 

[daves8]

If you have DPE headers, why are the back 2 in use? Presumably they would have had all codes removed?

I just replaced my front 2x with NTKs and they are doing well.

As I said in my original post, only the front 2 are active.

Do standard length work with 4-1 headers O2 bung location?

 

[dassaur]

As I said in my original post, only the front 2 are active.

Do standard length work with 4-1 headers O2 bung location?

Oh I see. The way you said it made me think the rear 2 were needing replacement.
Yes you get the standard length ones, and if you already have DPE headers they would have been installed with an O2 extension loom. Be aware that L77 and LS3 use a different connector. L77 is a flat connector, LS3 is triangular, even if the actual O2 sensor is the same.

 

[dassaur]

Also, I hasten to add, the location of the o2 sensor bung in the DPE and pretty much every aftermarket header is terrible. You really only get exhaust pulses from the top 2 cylinders.
While I had xforce 4-1, the bung location was the same and my o2 readings were way off what my wideband was saying. As soon as I put a bung about 15cm further back, lo and behold the narrowband and wideband were in agreement.

You can tell in the following pic:

 

[RevNev]

Also, I hasten to add, the location of the o2 sensor bung in the DPE and pretty much every aftermarket header is terrible. You really only get exhaust pulses from the top 2 cylinders.
While I had xforce 4-1, the bung location was the same and my o2 readings were way off what my wideband was saying. As soon as I put a bung about 15cm further back, lo and behold the narrowband and wideband were in agreement.

The DPE exhausts have a good note because the mufflers are packed with long haired fibreglass, but the design from the lousy header collector, wrong 02 sensor placement, restrictive X-pipe, trans tunnel brace delete etc is poorly done.

 

[07GTS]

was thinking that with my DPE, data looks like u have a miss in the 02's yet dont feel anything but its just the 02 picking up on the top two pulses, i have WB bout 6'' further back so might have to swap them round as the front is ok under loads just needs better feedback for the CL operation

 

[dassaur]

was thinking that with my DPE, data looks like u have a miss in the 02's yet dont feel anything but its just the 02 picking up on the top two pulses, i have WB bout 6'' further back so might have to swap them round as the front is ok under loads just needs better feedback for the CL operation

Try it. Your comments on HP Tuners forum made me think that way. On load it read OK but light load and especially idle the engine was running close to 20% lean!
Now I have the first set of bungs blocked, two bungs for NB about 10-15cm further down then WB.
Nb and WB within 0.5% of each other.

 

[RevNev]

Now I have the first set of bungs blocked, two bungs for NB about 10-15cm further down then WB.
Nb and WB within 0.5% of each other.

To correctly sample the entire cylinder bank and not a couple cylinders, the 02 sensors are best fitted at least 6" or 150mm past the collector merge or in the DPE photo, 6" further down from where they're located.