dangreene

Hey all,

2 questions...

What are the best value for money downpipes?

ALSO

Is a flash needed for downpipes or can it be run on a piggyback? (I understand there will be a check engine light if its not flashed, I'm more asking about the tune side of the car.)

Thanks.

shardul

iTrader: (1)

ECU calibration first.
You will need the ECU to be flashed if you install catless down pipes.
Another option is to by the Fabspeed O2 sensor extensions with cat material if you don't plan the flash the ECU
Piggy back will not be able to turn off the rear O2 sensors

RDO247

longbow0404

shardul

iTrader: (1)

Email me if you want a set

https://mbworld.org/forums/c63-c63s-...onverters.html

raudiace4

Where did you buy the O2 sensor adapters from? I'd like to run catless DPs while deciding on a tune or piggyback.

longbow0404

from my local muffler shop; I paid $15.00 for them...

JaeJin Sohn

I assume that running catless downpipes with just the O2 sensors will be bad for your motor and run really rich? I guess running rich is better than running lean tho. I'm planning on getting a tune in Texas or Florida or Cali and I'm in Illinois (lol). I really don't wanna pay for the labor of installing the downpipes because I can do that myself with my buddies. Yall think its okay to drive couple thousand miles with just the O2 sensors and catless downpipes?

skim7x

Why would dp's make your engine run rich?

JaeJin Sohn

I might be totally wrong here but in my understanding, reduction in back pressure will allow easier flow or air and cause the engine to run richer since it was tuned with the backpressure of both primary/secondary cats and the mufflers in mind.

Modio1234

more air and the same amount of fuel would cause it to run lean. Anyway I have a Chinese obd adapter with the torque app and a secondary cat delete from what I can tell the computer adjusts to keep the a/f the same.

JaeJin Sohn

If its okay to run the car without a tune with catless downpipes by bypassing and tricking the ecu for a while, I am interested in going catless downpipes. How can I trick the O2 sensor? Also, Im interested in that Chinese obd adapter and the torque app. Can you please tell me what it does and if its applicable for catless downpipes?

Modio1234

Running without a tune shouldn't be to big of a issue since the car should detect if it's running lean and add fuel that is how piggy back tunes work. The obd2 adapter and the torque app just lets you read all the sensors in the car and see a/f readout and clear check engine lights.