Gcuarino

Would like to run a nice exhaust and delete all o2 sensor's. Washington will no longer be doing emission testing. So better gas mileage a little hp gain, nice sound. I also would not like the check engine light to be on because of this. Is there a way to unhook o2s and maybe trick the brain? 1992 Lexus ls400 98000 miles. Thank you for any help.

RA40

iTrader: (6)

The ECU relies on that data to adjust fuel trims properly. There may be a way to work around this yet that may bring more issues. My suggestion would be to leave it.

HewittTech

I assume the OP is talking about the after cat O2 sensors. Yes, the upstream O2 sensors aka A/F sensors are needed for the computer but you can get rid of the rears with an O2 simulator. Basically an O2 simulator plugs/wires into the front A/F sensors and into the harness for the rear O2 sensors to simulate the signal the rear would see if the Cat was still in place to prevent your catalyst efficiency codes and the CEL from coming on. Another trick uses a spark plug plug non-fouler to place the rear O2 into the exhaust stream to reduce its exposure to the exhaust to simulate the signal. Both work find and pick your poison. A quick thread search shows a few things on the topic.

rick1987

iTrader: (1)

If you don't mind a check engine light.

But what I would do. Leave the first set installed. The engine needs these to run. The computer will probably throw you into limp mode if you disconnect them.

Ditch the Cat. And use a spacer for the rear O2 sensor. They might be called spark plug spacers.

I've used them in previous cars with gutted cats.

Gcuarino

Thank you for the info. I do wanna ditch the 2 cats. I don't want to hut them, but rather cut them off and run straight exhaust back. Can i still hook up modified o2s to just a regular round pipe?