Rear O2 and EGT help

[avsbmw]

Hey guys

I recently had the EURO headers installed and had my O2's relocated

My mechanic put the EGT sensor up further towards the headers than on the stock secondary cat section however it is still on the pipe before the headers. Does it need to be moved back?

I am currently throwing some codes
2C7F
2C6C
2C7B
2C6A
2C93

Any idea what might be causing these?

Two of the codes are O2 swapped in the wrong place however we took the section off and switched them and it is still throwing them.

Any help would be much appreciated.

[txz4]

the rear o2s should be behind the cats almost to the flange. The egt should be just about on the bend of the s pipe where it is larger than the normal pipe diameter. This is based on my euro cat section waiting for install hardware in my garage.

[johanness]

If u follow Euro spec:



OR

THREAD--> http://www.zpost.com/forums/showthread.php?t=614987

The guy moved his EGT into his headers with a substantial HP increase. However AFAIK he's the only one to have done this with any success. Could be wrong

[avsbmw]

Is there a reason the EGT is so far back towards the cats? Why would it not work further up on the section?

Does everyone who moves the EGT back extend the wires so it will reach?

[Jumbosock]

I think it's ideal to read the temp as it enters the cats. Some people do not add to the wires... they just pull out the slack.

[davesz4mc]

Why are we so worried about the rear o2 sensors? I understand it will throw codes but won't ess or someone just delete them from the ecu? The primary sensors adjust and monitor air fuel for maximum performance what are we doing with the secondary? balancing performance with maximum cat efficiancy?

[avsbmw]

yes i just don't like seeing the codes but not worried about performance from the rear O2s. However through a EGT plausibility code and trying to figure that out.

[Jumbosock]

Are you sure you don't have an exhaust leak??

[crfine88]

Originally Posted by avsbmw

Is there a reason the EGT is so far back towards the cats? Why would it not work further up on the section?

Does everyone who moves the EGT back extend the wires so it will reach?

Can't give you a specific reason why, but I can tell you that it does work in that position as I have modified my s-pipe to mimic the european version. Yes, you do end up extending the wires to reach.

Originally Posted by Jumbosock

Are you sure you don't have an exhaust leak??

This is a great place to start checking. A simple leak can send you on a never ending journey of tracking codes

[inTgr8r]

Originally Posted by crfine88

Can't give you a specific reason why, but I can tell you that it does work in that position as I have modified my s-pipe to mimic the european version. Yes, you do end up extending the wires to reach.



This is a great place to start checking. A simple leak can send you on a never ending journey of tracking codes

Or rework the routing without extending.

[johanness]

Originally Posted by crfine88

This is a great place to start checking. A simple leak can send you on a never ending journey of tracking codes

It's a never-ending journey where you'll want to because of that recurring CEL
Gets to the point where u just want to line up everyone and
Check for leaks X2

[avsbmw]

thanks everyone I will check for leaks and go from there

[inTgr8r]

Originally Posted by avsbmw

thanks everyone I will check for leaks and go from there

be sure to re-torque at the header flange as well.