DavidZhu

So i got the eurocharged V4 tune on my car about 6 month ago and now im throwing headers on as well. would i need a retune after i get the headers? im getting different information from people. and if i need a retune how much more gains would i get verses if i didnt get a tune? thanks.

aussie e55

contact eurocharged

Merc63

Yes you need a different tune.

mr747

Yes you will need a retune it will run really rich if you don't

You also get a check engine light

DavidZhu

so if i dont get a tune ill get a check engine light? andn what do you mean by runing rich?

AMG893

Running rich means it will cost you more (gotta be rich)

mr747

You will need a tune to lean the mixtures out a bit

You will most likely get the engine light and maybe require some new oxy sensors

loungn14

yes you will need a retune

Merc63

It will run lean, really lean.

More flow more air, and same amount of fuel.

anthonymckay

You need a retune after installing headers because you're significantly altering the airflow through the engine, which is going to affect your AFR (Air to Fuel Ratio). Your current fuel mapping is based on the assumption that you have the stock headers/airflow. You're also relocating your O2 sensors. Will it "run" without a tune? Sure. Will it be running correctly? Not so much. If you run a lean AFR (more air/too little fuel) you run the risk of burning up your engine.

mr747

My car ran really rich and then fouled the oxy sensor

Merc63

Strange tuners says lean and makes sense it would go lean from more air.

Maybe your o2s were messed up

abcut973

It makes sense indeed to think you would run lean after installing headers. So not too sure why yours was rich...maybe an aussie thing

mr747

MAYBE LOL

MaroonC63

HAHAHAHAHAAHAHAHAHAH

Yes. Definitely need to retune. Just email Jerry, he will take care of you!

avery.whss

my cars been running "lean" for months with CEL I just have 2nd cat delete..MB and no one on this forum has any idea whats wrong, (ive replaced everything) I've had no issues..atleast i dont gotta clean the pipes every 3 days now, so no i don't think running leans gonna blow the car up seeing mines been running lean for 5months+ and i beat the hell out of it

JPetros2008

A little unrelated...

But do I have to get a retune if I have replaced the secondary cats with straight pipes and replaced the resonator with an h-pipe?

avery.whss

from my knowledge no. I have straights and jerry told me no

DavidZhu

i called eurocharged and they said i need a reflash of my current tune

BO Knows

Eurocharged may be coming to San Francisco soon. ASP in Daly City is trying to set up a dyno day soon.
https://mbworld.org/forums/w211-amg/...yno-day-9.html

AMG Boost

Thank god someone on the forum knows what they are talking about lol.


Yes it will be lean. Headers free up alot of flow and your AF ratio will drop. This is dangerous because it can cause detonation.
Rich is when you have to much fuel. Also the 02 sensor could of been fouled because you removed your cats.