Another day, another mod. The next mod on my hit list is the restrictive exhaust system. After reading a lot of threads on this forum and other forums about magnaflow resonators, mufflers, race cats, etc, I had an idea. Another poster on this forum (kpeng) was successful in improving his exhaust system by having his muffler shop cut off the muffler and weld on two magnaflow round resonators with chrome tips. He even posted sound clips which sounded very good. The first thing I thought was "How cheesey" but the more I thought about it, the more sense it made. An exhaust system isn't rocket science.
What my friend Jack Daniels :dave: and I came up with is an idea. What if I bought the Supersprint headers (to eliminate the very resrtictive cats) and modified the stock pipeing from the SS headers to the muffler with magnaflow resonators and perhaps a high flow muffler, perhaps an x-pipe to get a less restrictive exhaust for a much cheaper price than a full SS header/race cat setup. I'm not worried about a smog test. The only technical issue I have is the pre and post cat O2 sensors. I'll get a CEL for sure. I looked at http://o2simulator.com/ as a fix but I'm not sure how my ESS software will interact with a fixed O2 sensor value. Any expert opinions?????? THANKS :str8pimpi
Is this the setup that you are referring to?
SS headers/factory midpipe or x pipe with some form of resonator/muffler?
Some people have claimed their cars ran like crap without cats, and I don't know of anyone that has gotten the simulators to work on an e46. I never went that route, so I can't say from a personal point of view. But I'm sure those people were telling the truth.
I recommend cats over resonators, it's the right thing to do and you won't get a cel.
If you were to purchase an x pipe from SS, that saves you about 1400 compared to a metallic cat, and by the time you get two magnaflow cats or the like, that's about $950 in savings.
$950 isn't that significant over savings than just getting the pre-made, high quality metallic cat from SS.
If you wanted to chop off your stock midpipe and weld in cats, than it's a more logical choice.
Is this the setup that you are referring to?
SS headers/factory midpipe or x pipe with some form of resonator/muffler?
Some people have claimed their cars ran like crap without cats, and I don't know of anyone that has gotten the simulators to work on an e46. I never went that route, so I can't say from a personal point of view. But I'm sure those people were telling the truth.
I recommend cats over resonators, it's the right thing to do and you won't get a cel.
If you were to purchase an x pipe from SS, that saves you about 1400 compared to a metallic cat, and by the time you get two magnaflow cats or the like, that's about $950 in savings.
$950 isn't that significant over savings than just getting the pre-made, high quality metallic cat from SS.
If you wanted to chop off your stock midpipe and weld in cats, than it's a more logical choice.
KP,
Thanks for the reply. You are correct "SS headers/factory midpipe or x pipe with some form of resonator/muffler" That is what I am thinking. I figured the o2simulator would be more trouble than it's worth.... If I were to install a cat in the mid pipes, what do you think about welding O2 bungs pre and post cat. Do you think the ECU would have an issue with reading the sensor values and throw a CEL? Could I extend the O2 sensor wires without messing up the voltage readings?? Thanks again. :bow:
KP,
Thanks for the reply. You are correct "SS headers/factory midpipe or x pipe with some form of resonator/muffler" That is what I am thinking. I figured the o2simulator would be more trouble than it's worth.... If I were to install a cat in the mid pipes, what do you think about welding O2 bungs pre and post cat. Do you think the ECU would have an issue with reading the sensor values and throw a CEL? Could I extend the O2 sensor wires without messing up the voltage readings?? Thanks again. :bow:
this is exactly what i want to do.. the only question for me is whether i can just stick ONE cat in the pipe and keep my rear res and muffler since i have a 323i which is one pipe through the middle.
KP,
Thanks for the reply. You are correct "SS headers/factory midpipe or x pipe with some form of resonator/muffler" That is what I am thinking. I figured the o2simulator would be more trouble than it's worth.... If I were to install a cat in the mid pipes, what do you think about welding O2 bungs pre and post cat. Do you think the ECU would have an issue with reading the sensor values and throw a CEL? Could I extend the O2 sensor wires without messing up the voltage readings?? Thanks again. :bow:
The SS headers have two bungs for the pre cats, so you don't have to worry about rerouting&extending the pre 02 sensors.
If you go with magnaflows or the like, I'm sure those have bungs on them as well. The question is whether the oem bungs are compatible with them. From what I hear, I don't think it's an issue since the people who have aftermarket cats other than SS haven't said anything about it.
I only know of a few people who have thrown CELs after extending the post 02 sensors, and yes, the problem was related to insufficient voltage readings.
The only thing that the post 02 sensors do is monitor the cat conditions.
You just have to make sure you use good quality/high temp wiring, and sufficient insulation/heat shield, because the cats and the midpipes get very hot.
I think the reason that the people who have gotten CELs even with cats is due to improper wiring extension. It's not an easy job by no means, but it can be done. Perhaps this thread may shed some light for you: Here .
If you have any more questions, just let me know...
If you wana sound like a race car, buy the ss headers and straight pipe it to a ss exhaust :evil:
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