pornstarSR

ok i have been asked this a few time to far so im gona post about it

On an ob2 car the way the 02 sensor system is set up is tha the primary 02 or one before the cat, usually on the header is for air/ fuel mixture control.....

the second 02 is only for checking if the cat is working....so what the second 02 sensor should see is a flat line of voltage....

the primary is always bouncing around adjustiing the fuel mixture, so if the second starts bouncing around just like the primary then the ecu will code.....

so my basic point of this is that if you have a test pipe you can just basically pull the second 02 out and hang it in the air, because its not going to move like the primary if its not in the exhaust steam, so you wont get a code.....and it wont code if its still pluged in..

i have had people ask me about the 02 simulators, in my opinion that is working on the same principle.....just cost you money.

but what ever you do dont put the simulator in the place of the primary 02 sensor

Sonny

The 2nd O2 sensor's voltage fluctuates as well. I can post a datalog if you wish. You can't just hang the 2nd one out in the open air. It's been tried a million times and you always get a code 67.

Sonny

pornstarSR

ok the 2nd 02 sensor on an OBD2 car should not fluctuate as much as the first one.....if at all....

and depending on the car your talking about, there must be something else going on to get you a code 67 because i have 3(one being my car, which i check with a master tech or scan tool for codes or anything out of the ordinary regularly) cars that i have made test pipes for in town and we all have our 2nd 02s hangin and havent coded......interesting, must have been the one and a million shot 3 times in a row

the point of it all is that the 2nd 02 is checking if the cat is working.... So as long as you dont put it back into the exaust stream if you have a test pipe you wont have a code.....because it will start to osillate like the primary.....which the ecu sees that out of spec and send the code....

also if you are talking about a datalog from a hondata i dont trust it because i know on hondata you can tell the ecu not to code if the 2nd 02 sees movement...

but even if youi showed me the datalog it cuiold easily be that the cat is bad on the car or not working properly.


[Modified by pornstarSR, 8:08 PM 11/20/2002]


[Modified by pornstarSR, 8:09 PM 11/20/2002]


[Modified by pornstarSR, 8:10 PM 11/20/2002]


[Modified by pornstarSR, 8:12 PM 11/20/2002]

falcongsr

i think honda uses different software algorithms in different cars and different years. and thats why some people get away with it and some dont. i think 96-99 obd2 ecus are easier to fool than the 00-01s - at least for integras. i didnt have much luck with an o2 simulator on my 00gsr

Sonny

Interesting findings...

Well, Zip's 02 Sim exists for a reason...it's because the ECU expects certain 'behavior' from the 2nd o2 sensor or it will throw a code.

AFA Hondata, what is there not to trust? It's based on OBD1 ECU's that don't care about a 2nd O2 sensor, so disabling it is not necessary.

What cars have you done this on? Some people with 96 year model cars report no ill effects of running a test pipe. Apparently Honda was still making the OBD1 to OBD2 transition that year.

Also, people don't always get a code right away. How long have your cars been running. Some people say that they don't get the code 67 until the run the car for several hundred miles.

More details please...

Sonny

pornstarSR

im not saying that i dont trust hondata, i think hodata is great, i was just saying that you can make a hondata not code.

i beleive falconGSR is correct.....but the thing is i did a test pipe on my car 98 civic, 97 type R, 99 SI....and we all did the same thing.....still no codes...its been about 2 months.

i talked to my mechanic here and he used to work for honda for 10 years....so he knows his stuff, he restated the same thing that i had said.....

but there could be differences....obd2 has 2 02's, obd1 has only 1

if on obd2 cars the second 02 osillates for what reason? the only reason that an 02 osillate is because the air/fuel ratio is changing, and if the second 02 is seeing this than tha cat is not doing what it should.

this happens everytime i post......someone tells me im completely wrong of full of it.

im only posting about stuff that i have personally done, or experienced


[Modified by pornstarSR, 9:46 PM 11/20/2002]

SuPeRITR

pornstarSR IS A JACKASS, DONT LISTEN TO HIM HES JUST FOOLIN U ALL!! HI HI HI HI

falcongsr

the 2nd o2 sensor should vary. the engine never burns all of the o2 that was sucked in. the cat uses some of this unused o2 to make CO2 and H20 and NOx out of the CO, HC, and NO that was either unburned or a byproduct of combustion.

based on how much of these individual molecules - including oxygen - determines what the cat is going to be able to do with them. if there are few unburnt gases /byproducts, then the o2 that enters the cat wont be utilized in the reactions to make water and carbon dioxide. if there are a lot of byproducts, then there will be very little o2 left.

1 thing i learned is there is ALWAYS excess o2 in the exhaust before the cat regardless of how much fuel you dump.

Tofurky

cool. santa barbara people

pornstarSR

Andrewww, Hi HI Hiiyeeee...


fix your check engine light JDM front end Boy

pornstarSR

yes there always is some reminants, but the 2nd 02 should not move as much the primary......

falcongsr

you're correct. i read an article about it today while doing research about catalytic convertors, and it should be much more constant, especially with the narrowband o2 sensors our cars have.

i am just going to get a 3" carsound catalytic convertor with an o2 boss in the rear for the secondary o2 sensor. no cat just stinks too much on a street car.

SuPeRITR

my name is sethanuel and im cool!! Everybody should listen to me cause im CRAZY. HI HI HI HIEEYY!! i would fix the check engine light if YOU KNEW WHAT THE PROBLEM WAS

pornstarSR

Well, if you didnt have captain e-tape put your POOPER CHARGER on and THEN TAKE IT OFF TOOOO then you wouldnt be having problems....

FIX your turn signals JDM boy

im gona get SPPPPOOOOONNN radiator Hoses cause they are BLUE