Been searching, and just wanted an assured answer from the more experienced people in this forum on the subject.

Just got my testpipe from SMSP, to run until I get all of the tuning elements in place, then a high-flow cat will take it's place for tuning.

My car, like many here, is OBD II.

Will running this test pipe with the 2nd O2 sensor just in open air somewhere cause the engine/ECU to make any corrections that would affect the rich/lean mixture of the car??

I'm a little paranoid, and don't know much about the O2 sensors and how they affect our cars, and really don't wish to do any damage to the motor until I get my VAFC in and can tune my car with the high-flow cat on the dyno....

TIA,
Jon

 

Secondary o2 won't change your a/f ratios but you'll get a CEL.

 

2nd 02 is strictly Emissions related. Nothing but a CEL basically....

 

So what I've come to understand is that the first O2 sensor has everything to do with adjusting a/f if the engine is running too rich/lean or detonating, thus will not change no matter what you are running (cat or testpipe)??

And the 2nd O2 sensor is just to let emmissions know if you are taking some of the pollutants out of your engine's exhaust??

So the reason why there is a 2nd sensor is just to try and realize a difference between the air flowing into and out of your catalytic converter? Therefore letting us know if our cat is busted and not doing it's job?

Thanks again guys...

 

And then the 2nd O2 sensor cannot put the car into 'limp' mode that will not allow VTEC to engage...correct?

 

yes to your last question. I am running the same testpipe on the ITR. I have the CEL right now, but it does not go to limp mode. is doing just fine.. I am not worrying about it until I decide which standalone I am going to use.

Eddie

 

Someone else chime in here. I think I'm running rich, and won't know until I get the tunign stuff installed next week. I was thinking the rear O2 was the cause, but this makes me think it's the front O2. Can anyone confirm?

I was throwing the CEL for a bit before I discovered the problems the former owner of my R left me with the exhaust (long story). It did not go into limp.

 

Same situation here .. JDM 4-1, test-pipe, Greddy EVO2 ... No Cat.. I have both sensors installed and I get the CEL but no noticeable problem with power ..

 

the only time the car goes into limp status is when it has a misfire or primary o2 problem.... the secondary o2 is just to ensure the cat is doing its job.

 

get a t1r resonated testpipe and make a o2 bung and u wont it wont throw a CEL