Hey everyone, so i'm kinda confused about the cel issue with installing a test pipe. I know if i run my car catless without an ems or o2 sensor fix the cel will come on and my car will eventually start to run in a "safemode" after a while where vtec is shut down and the car will run like shit. Is it something that can only be fixed with an ems? Or can it be simply fixed with the o2 sensor bug to trick the stock ecu into thinking the cat is still there? Any help will be great thanks!

 

With the test pipe the only code you should get is a P0420 for catalyst inefficiency... and that will not trigger limp mode. I've had good luck avoiding that code using the Vibrant Performance O2 sensor spacers... though I can't remember if there is enough room on the S to install one lol. I'll be under one this afternoon so I'll try to remember to look.

 

There is plenty of room for the spacer if your test pipe has the bung in the stock position.

 

Thank you so much! So i just want to clear it up, the o2 sensor spacers basically creates space between the o2 sensor and the exhaust gases so that it wouldn't trip the cel and trigger limp mode and have the car running with problems?

 

Correct, the spacer just places the O2 sensor further away from the exhaust gases. However, having the CEL (P0420 code as stated above) will NOT trigger a limp mode. My secondary O2 sensor failed on my last S, and I never encountered any issues other than an annoying light on my dash.

 

Oh i thought if the computer detects the test pipe it will trigger limp mode after the car has been driven for a little bit? Also this is probably a stupid question but does this apply to HFC? Like can the virbant o2 sensor spacer be used on a HFC?

 

I've driven with a CEL from:
-a failed secondary O2 sensor
-a test pipe w/o spacer
-an unhooked O2 sensor (one headerback I had didnt have an O2 bung)

and none of the above cases threw my car into a limp mode.

A friend of mine used a DIY O2 sensor spacer (spark plug defouler) with his Berk HFC, so I'd assume that the Vibrant spacer should work as well.

 

oh WOW its so simple I'm kinda shocked haha i was always afraid to run catless or with a HFC because i thought the CEL was going to be a big problem lol Thanks so much for the help