bnzuovr

I recently posted on here about blowing my motor after I had taken my car in to FLUID MOTOR UNION with custom headers & a re-tune out here in IL. I really do not want to get into too much detail about them (F.M.U) already makes me sick to my stomach to see what i went through to get my car running "RIGHT" again!!!!. Mainly what i wanted to ask all you guys/gals on here for your opinion. I noticed after the motor was installed and i reflashed the ECU car was running smooth but i had a heavy fuel smell coming from the exhaust do to the car running lean after i drove the car for a few miles the trouble codes would come on for a O2 sensor lean code not sure the exact codes but none the less it was running extremely lean. I figured it was the o2 senors gone bad but once i checked the sensors went back on my Alldata and checked the wiring connections i came to find out that my UP Stream o2 sensors & Down Steam O2 had been flip flopped when the headers were installed on the car. The thing i am not to sure of is this a possible cause for the cylinder to detonate and cause damage to the engine? Also would this effect the tune? And would i loose a significant amount of power? Since after FLUID MOTOR UNION installed the headers and re-tune my car put down way less hp/tq before the header and re-tune install. Just want others to be warned before they decide to get to modifying their cars, and also trying to get to the bottom of this since Fluid was not too much help other then the fact they offered to install the motor for me for free Thanks but no thanks .

skratch77

I would switch them asap to the correct sides,the car is adjusting the wrong banks for its fuel trims.

bnzuovr

Well they have been switched since i dropped the new motor in, After i drove it and noticed they were installed wrong. I just was trying to get some solid info if the tune would be effected and if it would cause any damage that was done to the engine.

skratch77

Is the car throwing any codes now?I thought you ment left and right were switched but not sure if pre cat and after cat would do.

So the precat 02s(the ones that see a/f) were connected to the rear post cats?

Car must of ran like crap!

bnzuovr

Yes pre cat o2 sensor (upstream) & post cat o2 sensors (downstream) were flipped meaning the upstream was on the down stream and vis versa. Car ran extreamly lean and burned a crap load gas as far as the way the car drove it really didn't drive any diffrent.

skratch77

Did you pay out of pocket for a new engine?

Roverron

What headers did you have?

bnzuovr

Sure did my friend and everything else that came alone with changing the motor fluids,gaskets,seals mounts,reflash,etc...... luckly i have a my repair shop so the labor i did myself.

Fluid motor union custom build some long tube headers. Was not to happy with them after i noticed the collector pipe was rubbing up against the stearing knuckle. SO their solution was to heat the pipe and bend it back with a pry bar and hammer along with grinding down the steering knuckle. I blame myself for even allowing them to touch my car.

ahmad0658

Thank god,

I kept away from them and went to Jeremy from OE Tuning, tune wise and price wise he is the best for me.

I advise anyone who wants to have a tune to dig a little bit inside the threads of this forum before tuning his/her car.

this following thread may help as it has voting on the tuner used by members:

https://mbworld.org/forums/w211-amg/...o-numbers.html

bnzuovr

funny thing about that ahmad is that they were sending my files to Jermey for the re-tune and at the time they said they were having a falling out with jermey i don't blame or accuse jermey of any of the issues i have had with my car. I belive something had gone wrong with fluid and the work they have done. My engine is not the first one that has gone "Bad" since they have worked on it. I talked to a few board memebers on the Bimmer forum and there has been a few others over there.

ahmad0658

A friend of mine here in UAE, told me that he has a friend who lost the SC of his car because of their tune, i am not here to blame them, but i am stating the truth, I saw the car by my eyes in the same workshop that my car was in for some upgrades, that car was waiting for weeks for that SC when they finally got one.

FMU tune is in the past for me, i am looking for better future now.

Jakpro1

Trying to image what the engine/ECU must think of the sensors being reversed.

It sees the lean ones first, then the post cat with more fuel.

Just can't think of what the car would assume is wrong. Maybe bad cats?

That is a trip!

bnzuovr

I belive you my friend, im sure your friends car waited for weeks if not months they had taken my car in to thier shop after i had it at the dealer and told me they would inspect the vehicle to see what was the cause of the detenation. after 1.5 months they gave me ZERO useful information other then the fact that the issues i was having was from manufacturer defect pffffff

saltydizzle

BUMP...would like FMU to chime in here.

jaguilar

what happens if an oxygen sensor is installed incorrectly