clk209nic

Guys wanting to remove my primary cats but don’t want the cel light coming on.

I have been given two options which the fabricator said won’t bring up the cel light.

open up and gutt my cats
or
instal tubes with o2 extenders

Iv searched and not getting a clear answer to this. Will this work or will I still require a tune to remove the cel.

The car has a tune on already but the tuners is few thousand miles away

sunnys14

If you have a V7 tune check engine light won’t come on. Eurocharged told me I didn’t need a retune when I cut my primaries off since the rear o2s are already turned off with V7.

clk209nic

Its had a Bevo Tune from the guys in the UK. The car is no exported so I won’t be able to get a retune. There reception wasn’t very helpful when I asked them for information regarding the tune other than a dyno graph.

if the rear o2s haven’t been turned off will the engine light still come on if I keep the original cats just gutt them out

The Machinist

Yes. The computer is comparing the front and rear gas flow to make sure the catalyst is still functioning.

If there is no difference between the front and rear locations, it will throw a CEL.

I have also never heard of anyone having any luck with anti foulers on their O2s to “fool” the computer.

It needs to be done right.

CaptnCharisma

I recently had luck with installing the VRP race pipes and just putting bung extenders on the rear 02 sensors. The car is tuned but it was from before I took the cats out and it's passed smog so I don't know what I am doing right.

roadkillrob

The c63 O2's seem pretty easy to fool, i have 200 cell high flows and just like 2 inch extenders and car is happy all monitors ready. With no cats at all you might need the extenders with the mini cats in them if just regular extenders don't work. Gutting your cats, I don't understand that, same as removing your cats, so you will still get a light unless you do extenders or something to fool the car or just get a tune and turn off the rear O2's but that will turn off the monitor so may give you issues passing emissions tests depending on requirements where you live - any tune will turn off 2 monitors so you will get 2 not ready results when they try to do OBDII for emissions.

robbyredneck

find some one with hptuners and just turn the code off

hachiroku

o2 mini cats are the most reliable in terms of preventing CEL for decatting. their prices do vary and can become pricey. gutting your cats will not prevent CEL and will actually cause it. J extensions have been shown to work most if not all the time for the M156 and it's computer as well.

If you have any interest in a custom tune of which you could spec the options of your choice feel free to reach out. additional information is available on the website. tuning is available remotely worldwide and any prior tunes can be overwritten. the factory original tune can be restored or custom tune applied.