Last year i deleted the cats from my bmw for better flow. I love not having them. But i have not been able to get inspected. Tried flashing to Euro software, tried o2 sims. Did not try spark plug de fowlers but i hear they are the least reliable. I have a single 3" exhaust. What i am looking is for the option to swap in a cat after the headers where the pipe merges into the 3", and swap it back out to just a pipe after inspection every year with V clamps.
Guess what i am asking is help choosing a catalytic converter that will keep my SES light off to pass emissions. And someone to cut the pipes, weld o2 bungs and weld the v clamps on @turbociv and extend the o2 wires.
I can’t speak for the BMW side of things but I had a CEL on for a code that often people often attribute to a clogged cat on Corolla. Went the anti-fouler route on the 02 sensor and haven’t had the light come back in 10k+ miles driving with it. I know your situation is different and you’ve probably researched the defouler method a ton but figured I would share my experience.
Yea the bmw dme is very touchy when it comes to emissions that method has worked for maybe 10% of the people depending on car model and which update is being used.
i’ve got two “spacers” on my rear O2 sensor and havent had a singe issue at all. but honestly, if you don’t have the stock converter you’re going to be spending quite a bit of coin to find a converter that will actually do it’s just up to the specs of the BMWs specs in the ECU.
Does spacing out the 2nd O2 sensor witih spark plug anti foulers work? I did that on my catless Spec V and it worked fine, it’s even working now on my fiance’s B7 A4 (using 2 of them stacked). Won’t know until you try Tom
Besides your usual Pep Boys spark plug fouler there are nicer options
They also have spacers that actually have a catalyst substrate inside them although I have no experience with these so I have no clue if they are effective.
The last option is to find someone who is parting out a car like yours or has ditched their cats to go with a race style exhaust and buy the catted portion on the cheap. Then swap it out come inspection time, but like you said, that’s a pain
It sucks bc factory Cats in the e46 are build into the headers So if i am to ever put one back onto the car it will be V-banded in right after the merge from both headers. maybe WE can try the spark plug fowler @Norb_O
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Again i have the stock headers. Not looking to go through 6 hours of hell once a year.
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I am going to try to get it inspected again soon, haven’t tried since using EU2. Just have to find an “IN”.
Buy 2 anti foulers, bring it over and we will throw it in. While working on yours I saw a bunch of wire loom, followed it to the open compartment on the pass side, and saw the oxygen sensors there…I was like WTF!
and extend the o2 wires.
that method has worked for maybe 10% of the people depending on car model and which update is being used.
So if i am to ever put one back onto the car it will be V-banded in right after the merge from both headers. maybe WE can try the spark plug fowler 