CEL from running cat-less (1 Viewer)

[CruisinEveryDay]

Hey guys I need your help. I have a custom exhaust set up and I am throwing a po171 system to lean code. This means she's throwing to much fuel in because there are no cats...

I have done a lot of research and talked to some guys who are running catless as well. They said I can fix the problem with an O2 sensor spacer. It basically pulls the downstream o2 further out of the pipe so the computer gets the proper reading.

Does anyone know where I can buy a spacer that will fit a 97 FZJ80 o2? Spacers are all over the internet but I can't seem to find one that will fit...

Thanks for your help and lets hope she wont have to be custom.

 

[hh65flyer]

I am running a replacement cat and occasionally getting a PO420 which is related (I believe) to the downstream sensor seeing too much flow. I want to try the spacer as well. It's my understanding that all the DS O2 does is look at cat efficiency which is determined by flow volume.

I don't believe spacing your DS O2 will eliminate your PO171 code. I could be wrong though. I think what's happening is the ECU is telling the engine to run rich in an effort to heat up your cat. That's not working though because your cat isn't there so the fault code says it's too lean (can't get rich enough). That logic would imply the DS O2 does more than just sense flow volume though...

I ran without a cat for a while and had both codes. Now the 420 only comes on every once in a while. If we had the simple screw-in O2 it would be easy to rig a spacer with spark plug de-foulers. But we don't. I'm thinking I will try to make my own out of some plate steel.

Hopefully someone will reply with a source for a proper spacer. Good luck!

 

[LFD2037]

I think for our rigs you have to make your own. If you have old exhaust pipe from an 80 you can cut the O2 sensor off it and weld it on top of the mount that's already there. Then you'll be spaced out about 5/8"-3/4".

 

[CruisinEveryDay]

Thanks for the replies guys...
hh65flyer- I will pay you to make me one as well haha but really I will

 

[bsmart82]

A p0171 sets when the ecu detects a lean condition. It will not set from a missing catalytic converter. A p0420 would set due to a bad or missing cat.