Does running catless cause problems with the 02 sensor in a L03?
And are there modules avalable to replace the sensor in this case? (as seen on Lt1 cars)

 

I can't see how deleting the cats (or gutting it in my case) would have any affect on the O2 sensor's operation.

My L05 seems to be OK, though I haven't confirmed with a wideband O2 (good excuse to dyno)...

 

I deleted my cat after putting headers and complete 2 1/2in exhaust with a flowmaster 80 series on. I had problems with the 02 sensor not getting a constant enough reading due to the lack of back pressure. Maybe my sensor was bad, 'cause I changed it to a broadband and it works fine. But I was told that it just might have been the backpressure that caused it.