sturte30

I am interested in the Renntech tune for my 2014 E63 . If I were to get the upgrade now, and then update to catless down pipes at a later date, would the ECU need to be reprogrammed again to account for the new pipes (and clear the check engine light) or are the lamda sensors already turned off in the out of the box tune?

kponti

From experience, ask for the tune for downpipes from the get go. Or you will have to pay an additional 900-1200 for an updated tune. You can run the catless tune on a catted setup since all they do is turn off the rear O2 sensors anyway.

The retune is only free is you buy a Renntech downpipe

gaspam

I did exactly this when i first got my car. You need to retune to code out the check engine light you will get from going catless. other than that though, the renntech retune does nothing else, its just them going in and coding out the cats.... everything else from the original renntech tune stays the same (timing, boost, etc...) so if you dont mind the check engine light, you can run the catless downpipes with no retune for as long as you want...

I did the re-tune because the check engine light was annoying me everytime someone got in my car and was "whats wrong with your car? the engine light is on..." , plus renntech is local to me so its easy to pop over there and get it done in an hour... if i had to ship my ecu i might of procrastinated longer

sturte30

So after talking a bit more with my dealer that is the Renntech distributor, they said that Renntech does not (and won't) turn off the rear o2 sensors for catless down pipes. I am sure this is to sell more of their crazy priced catted pipes. Has anyone had any luck with o2 sensor extensions to get the the sensor out of the direct path of the exhaust? Or is there any thing else out there like an o2 simulator that can be plugged in to trick the ECU into thinking the rear o2's are there?

Thanks

Ralcbah

Hi. I suggest you call renntech directly and tell them what you're looking for.

sturte30

I tried that as well. The response I got back from them was well, we don't sell catless downpipes. I said I understand that but I'm asking if your tune can turn off the rear O2 sensors. They responded back with let me check with one of our techs and find out. That was the last I've heard and it's been over a week so they are not being too helpful.

LaunchPad

You could get a tune and downpipes from Eurocharged for almost the same amount of money than just a tune from Renntech Something to keep in mind

iownedu

+1 for Eurocharged.

sturte30

I am CPO and the dealership said that they won't void a warranty with a Renntech tune (even have it documented in an email from them) so I am trying to keep the CPO status. Otherwise I would look at others.

iownedu

I have warranty as well and understand why you wanna go Renntech then, they are a good tuner, just expensive.
I decided to take the risk and if I lose an engine I'll just pay to have it built stronger and add larger turbos.

Ralcbah

Unfortunate they've yet to get back with you. Try em again, especially since you've already determined they are the group you'll go with. Can't imagine they won't work with you on this, but who knows.

gaspam

I have renntech tune and catless downpipe's and they turned off my rear O2 sensors so unless something changed in the last six months something sounds fishy .... also I tried the O2 extenders before that and they didn't work to eliminate cel

ultimately if they say no, and if you still want catless downpipe's then just get them and drive around with the check engine light on, no big deal

If all else fails, just give up on the downpipe's as it's not like you're going to pick up a ton of power anyway.... I really can't tell much of a difference before and after other than the noise and if you're just looking for the noise you can accomplish that with some renntech mufflers

TMC M5

Maybe they don't want to admit over the phone they play with emissions in any way.

LaunchPad

I have the Renntech intermediate tune ? The highest one (it came already on my car)Also the Renntech step colder plugs I bought an aftermarket extended warranty and was assured the tune wouldnt be an issue I havent had to make a warranty claim as of yet but I have my doubts if or when I do.

Amg63-

you must have the renntech full tune, not intermediate.

Funny how Eurocharged has it very similar, stage 1 tune and then also stage 2 rocket tune which requires upgraded spark plugs with different gapping than stock (.021)

i feel like if dealer can blame the problem on the tune they will use that as a way out. We are definitely taking a risk here.

LaunchPad

Yea I have the advanced one. Yes some risk involved but I wouldnt want this car without a tune. That being said I will pay to play If I have too.

vcci

After getting RT full tune I didn't feel downpipes were necessary.

Amg63-

as in the car is fast enough already?

i feel the same about the ec full tune. Crazy fast without adding DP already.

sturte30

I would just like to hear the turbo spool more. I love the sound on a cold start but then the turbo sound dies off once it settles in

LaunchPad

Swapping the air filters to BMC or similar will make the turbos louder as well

chiromikey

I swapped air filters before DPs and didn't notice a thing so I guess ymmv...

vcci

[QUOTE=Amg63-;7027020]as in the car is fast enough already?

yes, I can't imagine having it without the tune

I have BMC filters and though i do hear the turbos they are not very loud and i'm not sure if the BMC made them louder or possibly the tune?

sturte30

*Update* Renntech did finally get back to me after bugging them again and they confirmed that they can tune out the rear 02 sensors with their tune. Looks like some Rado catless downpipes are in the future