fatbillybob

Guys,

I might not get time to have my second 02 sensors turned off before my next trackday and get tuned after my exhaust mods. I suspect the MIL's for downstream o2 sensors will turn the MIL on. Will that doing anything to my engine performance or just turn on the MIL?

Thanks!

davidfarmer

I think it just sets a code, I don't believe they are used for actual engine management.

Rob's 73

They are just there to verify that the CATS are working. Ignore the following codes if they show up.

P0137
P0138
P0140
P0141

P0157
P0158
P0160
P0161

exracer28

The 2nd set checks that the cats are working. Remove the 2nd sensors, plug the hole, and secure the removed sensors.

Jason

Will they still throw a CEL?

drivinhard

it will trigger the MIL, no performance effect

you can turn them off easy in HPTuners.

exracer28

They will not throw a code if removed from exhaust flow but still connected to the harness. Basic evaluation made by ECM is 2nd set air cleaner then set 1.

Rob's 73

If you leave them connected be careful on how you secure them. They get very hot.

Jason

Be one less thing to f with when dropping the exhaust.

exracer28

On my cars I use radiator hose clamps and clamp to the exhaust. Benn on the car for years but I do check each time I change oil.