hi guys...
a friend of mine from Taiwan changed the exhaust on his TT...
and the check engine light is on...

how do you void this problem? or solve it?
I know it's quite common among tt cars ^^"
btw...i believe he's using techart exhaust w/ 200 cat

 

he probably put the 02 sensors in the wrong way around...

 

Bet you are right. Either that or they are not tight in the exhaust. What is the code?

 

I'll try to get that info asap ^_^
he had the techart exhaust w/ fvd header... then he thought the techart exhaust was the cause, and switched to fvd exhaust... problem still exist...

there aren't that many good tech who knows what they're doing in tw... and they're suggesting him to do the eco mode to bypass this problem...

i'll try to get the code asap... thanx for the prompt reply Alex & Stephen ^_^

 

Dear Stephen and Alex:
Here is the result...
"O2 sensor efficiency ahead cat. Bank1" "O2 sensor efficiency ahead cat. Bank2"
These are the codes that appeared...
The owner contacted the tuner in US (don't know which one), and they suggested welding an extra pipe around the sensor area to void such problem, and they did... however the problem still exist... (i feel kinda sorry to see the exhaust being mod like this)...


After that... I believe they changed the exhaust (w/ no modification to the exhaust)... and now the code turned to be "Cat. efficiency Bank1" and "Cat.efficiency Bank2".

What's the problem here?

 

Hmm, that's interesting what they have done there. Has anyone confirmed the O2s went back where they should be. Am I to assume that there are no cats in there? f not forgot it. You will never be able to get it to stop.

Lastly, failures on both sides and cats in place indicate a MAF issue, not exhaust.

 

thanx... stephen ^_^
sorry that i'm not quite familiar with the tech parts...
just wanna get it right, do you mean that the code indicates the problem arised from the O2 sensor?
and there is cat in there...(200)...
how should it be resolved? and what's MAF?

 

The whole "welding a pipe around the sensor area" thing actually works, but it's not a pipe, it's actually a pretty precisely made spacer. Subarus have that problem with aftermarket exhausts. One fix is the spacer, another is wiring a resistor in where the O2 sensor used to be, to permanently shut off that particular CEL.

MAF is Mass Air Flow sensor, it's somewhere in the intake path. The MAF has a heated coil in it, and as a specific amount if air flows past it, it cools the coil, creating a voltage that can be read by the ECU. The ECU takes this info and uses it to properly map fuel and timing.

 

a guy i know suggested to use a resistor to give off teh same signal as working 02 sensor too

 

You can not trick the 02s. We have BTDT and have tried everything including active circuits. You can only shut them off in the program which is not something done due to emission laws.

 

so Stephen:
do you suggest checking the O2 Sensor first to see if they're installed properly? what should be done if it's placed right?

 

Its sounds like to me the sensors are reversed, or you have bad cats. Check the sensor installation, if that yields nothing then look at actual values (live data) fields , for the four sensors. While doing this, vary the rpms and the data (waveforms) should mimic one another B1S1, and B2S1 should appear the same. As should B1S2 and B2S2 should also appear to have the same activity.
However having two of anything fail, sensors or cats leaves me a little suspicious that the problem may be something more basic, like installer error, or a bad maf, as Steven had correctly pointed out. Good luck on this one....
Howsit Sharkey and Steve? Lets go back to Vegas!!!

 

My wife wants to come this time...Back to where we all went before LOL, I am game!

 

Heeeeyyyyy now that is EXPENSIVE!

 

I showed my wife the pics of the Victorias Secret models that were in the Hotel with us, and she wants to go to Vegas next time I go, for all the right reasons....yippeee