performance mods
 

Has anyone done any resistor tricks to trick the MAF and O2 sensors? If I removed the catalytic converters on my 99 2.5l for "track" use, has anyone tricked the computer with resistors in place of the O2 sensors?

The proper way to do this is to get a different DME flash, appropriate for countries without regulation. It can be done, but not many talk about it.

Another option is to just not worry about the CEL. It won't hurt perfomance.

It will hurt performance ...
 

... If you remove all of the O2 sensors.
Monitoring the exhaust by the O2 sensors is the only way the engine management can adjust the mix and obtain the best performance.
What you don't need for performance are the cats and a second set of O2 sensors.
For track cars we remap the ECU to RoW specs which allow the user to remove the cats, the second set of o2 sensors and the secondary air injection pump.
Happy Boxstering
Pedro

That's what I was concerned about is that the computer does make adjustments to the air fuel ratio and timing according to O2 sensor data. My 99 2.5l has pre and post cats. I know cats are restrictive. What are my best options for opening up this portion of the exhaust system?

yeah, don't pull the pre-cat O2's. They are required for proper engine operation, the post-cats are just for emissions compliance and you can ignore the CEL that they will throw when removing cats