This is a DIY in 4 Parts
DIY: Downpipe (DP) installation for E90 335i
Please Note: This was done on a '08 E90 335i with Ultimate Racing catless downpipes. Any variation (different model 335i, different downpipe vendor, etc.) and your mileage may vary! Also note: if you are an...

Agreed, incredible post man....

Thanks for taking the time to write this up!

Any of you guys have problems fitting under there with just rhino ramps? I want to figure out if I need to buy jack stands or not.

i havent done the DP installation but I do have rhino ramps. depending on how big of a guy you are it may be slightly tight.. i am 6'3" ~200lbs and i can slide under the front no problem to get to, say, the oil drain plug.. maybe those who have done the DP install can speak more to the room for longer time installs.

if you do get the jack, i suggest you also pick up the aluminum jack pad... i would have gotten the jack if i had found this before i bought the ramps
http://burgertuning.com/BMW_jack_pad_adapter.html
it fits right into the build in bmw jack pads

thank you for this fantastic DIY. it's very thorough.

Nice DIY. I'll be using this next week when I get mine.

Great work!

Great DIY, followed every step and finally got my DP's installed, im not going to lie it was a major pain in the ass..

Stupid question but I have to ask. When unbolting the steering rack completely is there any reason that the car would be out of alignment afterwards? I didn't think any of the alignment points were affected by the steering rack removal.

thanks!!!!

Thanks for this DIY. I did it this weekend. And like Toker said above, it was a pain. But it would be much easier the 2nd time around, if there is a 2nd time (which there better not be). LOL.

Is the effort worth the result? I'm leaning towards getting one.

After doing this I thought I had the same issue. Turns out I didn't tighten the bolt you just untighten (but don't remove) to pivot the steering rack all the way. After tightening this, everything was fine. I'd double check those 2 bolts first.

great DIY thanks for putting the effort

I just got done doing this and I can honestly say that I will NEVER put downpipes on another 335 for as long as I'm alive lol. This write up was awesome but I was almost ready to just throw my dp's out into the street at certain points.

Ha ha! I feel your pain, Bro. I had home on a lift and it still took me 7 hours to complete. I think It will take less than 3 hours next time though. That is when I have to put the stock ones in for a smog inspection. It's still very much worth it I believe.

I was on rhino ramps and it took me about 7 hours also split up between 2 days. I still need to get under the car again one day and figure out where my rattle is coming from. I adjusted my wastegate and got rid of one rattle but now I think my DP's are touching and causing another from time to time.

Great DIY, Thanks

i'm scared shitless to do this install (thou i've installed all the mods on my car, including lowering springs)

the one part that scares me the most is the steering rack part...... would be perfect if there was some more details and pictures on that part... or maybe i just need to read this DIY 50 more times


have also looked at this video 20 times...

catless DP install

That was SUCH a helpful video. Thanks buddy!

as i'll be doing this pretty soon. today i got under the car just to look around and pretty much removed the stock down pipes (i know i'm crazy) ......... is not as bad as i thought. now i gotta buy the catless dp...... damn AA downpipes are out of stock till monday.

started this tonight after i got home from work and worked on it for about an hour (in the dark with iphone flashlight app ) and im down to removing the front o2 sensors and the upper dp clamp bolt and they are out. will resume tomorrow morning. not so bad so far.

wish me luck.


edit: finished everything this morning in about 2 hours + 1 hour yesterday = 3 hours total for the job. not as bad as i thought. AA downpipes fitment was spot on. not one hiccup during the whole install.

thanks for the DIY.

Great job writing this up