New exhaust.. O2 warnings.. TUNED.. still Check Engine warnings!?!!?

[MACDOOGAL]

Hey all,
I got a feeling i'll get the 'use search button' posts by some people which is fair enough because i know there are alot of threads on this general subject.. ive read them. Problem is though I had my SSV fitted with a catback 3" system and the check engine lights come on, as they seem to for everybody.
After reading a few of these threads i opted to get the car tuned, as the concensus seemed to be that tuning the car will fix the problem. So i dropped into KPM today and had one of there 'flash tunes' done for $490 where the guy garaunteed me that'd would fix the problem... Anyways picked it up, all good, drove bout 10 - 15ks then the 'check engine' light pops up again???
Soo i took it back to em and now they seem to think that one of the sensors may have been damaged with the initial 'smoke' or something from the new exhaust!? So another $150 and there replacing that tomorrow....
THE REASON im on here though is they dont seem too confident, and ive already sunk the $490 into it for nothing, so just wondering if anyone has any ideas or even better experienced and solved the same problem???
Cheers!

 

[RiCeY]

lol @ smoke, take it to someone who knows what they are doing, they obviously dont.

 

[MACDOOGAL]

Yeah i figured as much.. Seems like every place i spoke to had no idea what they're doing.. One joker tried to tell me they'll just reset the system and the car will 'auto-tune' itself.. Another company said the sensors might be too far away from the cats...
Does anyone know if just switching the post O2 sensors off will do any damage to the car??

 

[RiCeY]

The pre and post cat sensors work in unison so you cant turn either off or youll get constant error codes because the ECM cant compare each sensors values.

From memory the positioning/distance of the sensors is what throws the error codes.

 

[bladerunner]

I'd get in contact with vcm suite in melb. they are one of the pioneers in LS series engine tuning and know their stuff.as for the sensors, what smoke?it's a bolt on system isn't it? therefore no welding,that's the time you'll see smoke when it's started for the first time and all the weld smoke gets blown out. your engine won't blow smoke because of an exhaust change. the post sensors should have been switched off with the tune, which sounds like they havent.they are only heat sensors anyway that's why your light came on a few k"s down the road I bet.

 

[Lumps of cheese]

From memory the positioning/distance of the sensors is what throws the error codes.

That's it. Going from standard to 4 in 1's throw the code. Mine did this and after my tuner sent me my tune and i put it in all was fixed.

 

[MACDOOGAL]

The pre and post cat sensors work in unison so you cant turn either off or youll get constant error codes because the ECM cant compare each sensors values.

the post sensors should have been switched off with the tune, which sounds like they havent.they are only heat sensors anyway that's why your light came on a few k"s down the road I bet.

So they can be switched off or will that make things worse!? Have you had yours turned off bladerunner?
I don't think the distance is the issue because it's only one sensor that's setting the alarm off...?

 

[bladerunner]

yes my rears are switched off. when a tune is done such as yours its standard procedure to switch the rear(post cat) sensors off. it doesnt matter if you have a full system or a catback they are turned off as like i said they are only heat sensors and wont do damage to your engine. but since you have just said only one is playing up-how do you know its only one, was a code check done?- then maybe its a front o2 sensor as the rears wont show anything obviously if they are switched off. dont despair mate i'm sure it will be sorted.

 

[Sabbath']

yes my rears are switched off. when a tune is done such as yours its standard procedure to switch the rear(post cat) sensors off. it doesnt matter if you have a full system or a catback they are turned off as like i said they are only heat sensors and wont do damage to your engine. but since you have just said only one is playing up-how do you know its only one, was a code check done?- then maybe its a front o2 sensor as the rears wont show anything obviously if they are switched off. dont despair mate i'm sure it will be sorted.

:hmmm::hmmm:

 

[MACDOOGAL]

The rear sensors are definitely still on, the code that come up on there computer said it was the left rear sensor setting it off.. They said Not to just turn em off BUT if you've done it to yours and she's fine I mite just ask them to do that if the new sensor doesn't fix the problem