Im just curious to know if using test pipes are bad? I have them install on my 2007 350 and I know the cats burn unused hydrocarbons and the o2 sensors use that information to adjust the air/fuel ratios so the engine runs smoothly. When cats are not installed the o2 sensors read a higher amount of unburned fuel and hydrocarbons, thus giving bad info to the ECU and making the engine running poorly or am I just retarded?

 

You need to run a O2 spacer/non-fouler with test pipes, so the O2 sensor is out of most of the exhaust stream, but still gets enough info to function. Not sure if the car would run worse with test piper and without the O2 sensor spacer though.

 

I have AAM test pipes and AAM exhaust it all sounds awesome but I wonder if test pipes will actually hurt the car in the long run. The test pipes do have a huge spacer on them a none fouler its called. I bought a scan tool and download to DTC's and came back with a P0138 which is Rear O2S, Bank 1 Maximum Voltage Monitoring. Not to sure what it means and if I should continue to drive it and keep resetting the code. I also got a p2A03 and I have no clue what that one means. Any advice would be cool.