primary

Hi I bought the front pipes to take out the secondary cat and opened it up today and I thought the car had sucked in a pussy cat as all is in it is hair. I am doing it to get a bit more of V8 noise but am now wondering if I have wasted my money. Is there anyone who has removed the "cat hair" and...

Got the itch to mod the car, so far i have got the basics, secondary decat and res delete and eurocharged v5 map. I was reading that the primary cats are 750cell!! and am looking to swap them out for 200cell. I saw palmball's mod of gutting out the 750cell and welding in the 200cell in...

I mentioned on the MSL Dyno day thread that I'm having the n/s primary cat looked at by the guys at Torqueflow next Sunday. But something happened this morning that does concern me more than a little. There was a big thunderstorm in Poole this morning and I slowly drove through a huge puddle...

There seems to be plenty that have done both primary and secondary cat deletes on the us sites but has anyone done it on here? A lot of them over in the us just gut there primary's and use extenders so it doesn't throw a cel. There is talk of having to use a crossover pipe when both primary...

Guys, If you already have your secondary cats deleted will replacing the primaries with sports cats cause an mot issue or eml? Thanks

Hi I'm in need of a new primary cat for a CLS55 and finding one impossible to find without spending alot on a new section of exhaust and three cats. I've noticed a few people running race cats and wonder how you get on with emissions test, longevity and noise etc? May be a way forward if no...

Had car down workshop on the ramp yesterday to look at removing secondary's and thought as the exhuast will be coming off I could take out the primary's as well. What is required to turn the light off that removing primary would throw? Is gutting the primary's worth the hastle? Apart from...

Hi all, I've watched loads of videos of people who have removed secondary cats and or resonators. To me, personally, a lot sound really raspy and un-refined, more like a shouting car rather than a deep rumbling puuurrrrr like the original C63 sound. I just watched this video, I think, going...

Hi all, I have a bad misfire problem on my car (only on the second bank - P0300, and P0305-8 errors), which I am slowly diagnosing. One of things suggested on many forums is a blocked cat. At the bottom of the downpipes, there are very small looking silencers, which I assumed were the primary...

Are they regarded as reliable as a primary/boot drive or more risky than a traditional disc?

I thought given some new photo's are available, I'd treat this modification to it's very own thread. The modification of headers and cats was very much a last minute decision but as you'll probably know, my car is out in Germany this week having the final adjustments made to it's suspension...

I know this is a question that never gets fully answered so maybe I will be able to shed some light on it. I am going to remove my main catalysts this week(hopefully, depends on the weather LOL). I know there's not much to be gained by removing them and maybe even a little less torque, but my...