Ok say I get a test pipe and it throws a CEL. Will the CEL cause the ECU to switch to a safety setting and cause the engine to take a loss in performance, ie no VTEC more conservative fuel map, retarded timing, etc.??? I've heard some things about this while others say that there is no such thing as a limp mode. Anyone know for sure?

 

I've thrown CELs w/out having to go into limp mode, and once that made it go into limp mode. The limp mode capped the motor speed to 5K, but was fine all the other times. It depends on what CEL code you cause.

 

What about a code for the o2 sensor in the cat like when installing a test pipe? Will that cause the ECU to switch to limp mode?

 

Yes. My friend dynoed one time and he forgot to hook the o2 sensor back in. It just went into safety.

 

THe secondary O2 sensor error WILL NOT cause the car to go into limp mode. ONLY a CEL.

 

to eliminate ur cel for the o2 sensor not being in the cat or just sitting there wrap it up with aluminum foil, everything will be straight , no check engne light for a while now


[Modified by On Point EK, 7:29 PM 4/11/2002]

 

did u just leave the rear 02 sensor hanging and then wrap it in foil?

 

zip tie it to somewhere in the engine bay, tha wrap that bitch up co cel for a while, I believe Artturbo told me about this

 

cool, im gonna try this tommorrow when we put the boost controller in

 

ok i gotta clear this up a little
not EVERY code will cause limp mode. i ran without an o2 sensor for a month everything worked fine.
Limp mode is for a problem thats significant. like if your VSS isnt working (vheicle speed sensor) then its no vtec, no spedo, no odometer.

 

no limp mode for O2 codes- just operates in open loop with a yellow light in your face.