Stock midpipe on a car tuned for an O/R midpipe

[jaehow23]

Guys, quick question...

If a vehicle is tuned to have an O/R midpipe on it (all monitors left on in the tune) would putting the stock midpipe on it make it throw a code? Or would it just run bad for however long the stock pipe was on? I'm asking because CA smog will have to do a visual check and the vehicle has to have cats on it. If anyone knows, please respond.

Thanks.

 

[TaraFirma]

If all monitors are on with the OR pipe and you're not getting codes (don't know how) then you'll be fine if you put your stock pipe back on.

 

[jaehow23]

there are currently no codes (mil eliminators I'm assuming). I'm just making sure swapping to a catted midpipe won't cause any rich/lean codes to pop up when I take it in for inspection for a title transfer.

Thanks for the response.

 

[decipha]

no it shouldn't cause any issues, any competent tuner can leave the rear o2s on and just adjust their thresholds so they always pass even with them unplugged no problem