MIL sensors, and cats.

[ASSEMbler]

I assume the sensor foolers are just a resistor? That makes everything seem ok from the rear sensor.

If I replace the cats with hi flow , I would need four foolers right?
As there's 4 cats?

Basically I ordered long tube headers and flowmast 40's and I want to put in high flows.

[Danger Dude]

NO you dont need 4 there are only 2 sensors

[ASSEMbler]

Thanks

[Crispy]

Speakin of sensors, im runnin H-Pipes, and my Check Engine light is on. Anyway, I heard that with the light on the car runs differently, more sluggish than when the light is off, does anyone know if thats true or not? Also, where can I fidn the MIL eliminators at a good price, i saw them on ebay once for $35 and havent seen them again since. I've also seen homemade ones for $15, im a bit iffy on the quality of those though. Any help is greatly appreciated since i have my inspection coming up in February.

[tire]

yes the front two are 02 sensors... if you are getting longtube headers you'll need extenders (yes they sell them) to have them reach an extra foot to the base of the collector.

[Ponycarman]

Here's how the 4 O2 sensor systems work.

The 2 O2 sensors closest to the engine are what tells the computer how rich/lean the engine is running. If either of those fail/get removed then the computer goes into "limp home" mode and runs richer than normal.

The 2 sensors after the cats tell the computer how well the cats are working. If the output from these sensors starts matching the information from the two sensors by the engine the computer assumes the cats have failed and throws a code. If you axe the cats the computer doesn't know that (unless you reprogram it) and sets a code. The MIL eliminators essentially fake the signal from the rear O2 sensors and fool the computer into thinking the cats are there and working.

Steve