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So now I have only my Custom mufflers, more power from 0-100
more noise also, be aware
I kept my OEM X-pipe part as it has a very special shape
as you can disable downstream CATS (the pair after the Cats) in DAS developer, I tried that but really stupid, a message telling CAT heater doesn't work shows up so forget that
just make a little socket for the two cats from metal (metal because the heater temp goes up to 250 degrees Celsius)
and hook it up like me
Close the tube with black 250C° gasket sealant (sensors don't like water)
disable the line I am showing in DAS
perfect !
have fun !
Read my posts before you go into the wrong direction with DAS / Xentry Diagnostics
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Last edited by pmercury; Jan 15, 2020 at 09:22 AM.
I forgot to mention
In the back before the mufflers there is enough space to hook up the CATs
so I made a quick connect piece there to reconnect the CATs every 2 years to pass controls
you just need to heat up the car a bit before the control as the CATs need to be hot to work
closer to the engine is faster but no space
It's nice to see that you solve a problem with cats in different way than extenders etc.
Please tell me it's no CHECK ENGINE light or errors after delete ?
Do you make any o2 supply inside lambdas connector like little hole in it or not ?
Do you have a problem with exhaust smell after cat delete ?
I am thinking about that mod becouse it can give us about 40-50HP additional ( Speedriven told that about 80 HP ), but I don't know it's a good idea to cabrio.
It's nice to see that you solve a problem with cats in different way than extenders etc.
Please tell me it's no CHECK ENGINE light or errors after delete ?
Do you make any o2 supply inside lambdas connector like little hole in it or not ?
Do you have a problem with exhaust smell after cat delete ?
I am thinking about that mod becouse it can give us about 40-50HP additional ( Speedriven told that about 80 HP ), but I don't know it's a good idea to cabrio.
no errors if you build the double lambda part like I did
no holes as you disable them in DAS, you can't disable the lambda heater control, that for only you need to make this
I tried adding spark plug de fouler extensions but the transmission gets in the way and I can only add one extension each side unfortunately
I want to try this idea, I’m just not sure where to find the right metal tubing for 18mm on both sides
also need some spare o2 sensors to plug the old holes in the exhaust, my spark plug anti foulers are 18mm so that leads me to believe I can just buy two spark plugs that ARE 18mm each and plug them into the old o2 bungs? Sounds silly but cheap at least
I’m too impatient , I went ahead to the hardware store to find a solution. I used steel tubing for the housing of the sensor assembly pmercury engineered, used some copper pipe to reduce the steel pipe down to the size I needed to re-use my spark plug defoulers. See photos below
one thing that has not been covered in this thread I don’t think, see I did not have this endgame in mind when I had my cats deleted. I left the original o2 sensors in place and the bungs also. So now you ask “I have two open holes in my exhaust now, I can plug it with 2 spare o2 sensors but those are usually at leas $30 each for o2 sensors.
what I did is I realized there must be an 18mm spark plug that exists, since I was able to buy 18mm spark plug defoulers. The 18mm spark plugs belong to the 90’s Ford l6 engine for reference
spark plugs are about $2 each, so they made a suitable diy plug for the old o2 sensor bungs. I’m waiting for my exhaust to cool so that I can install everything up
dont forget antiseize.
Last edited by ctravis595; Feb 17, 2019 at 04:47 PM.
Reason: Add photos
Oops , just realized you mentioned to disable the secondary o2’s in star after doing this mod. I came back to ask if you have secondary o2 error codes and now I’m realizing this was probably my mistake
its a seldom occurring but every once in a while I will get a p0157 code , sometimes also 0137 but not as frequently.
These always show up with my p0131/0151 codes, might be worn out primary o2 sensors; may be an air/fuel issue also.
edit- now I see why I was confused, your original post says to forget about disabling secondary o2’s but then later mentions to disable them. Which one did you do?
Last edited by ctravis595; Apr 13, 2019 at 04:06 PM.
Oops , just realized you mentioned to disable the secondary o2’s in star after doing this mod. I came back to ask if you have secondary o2 error codes and now I’m realizing this was probably my mistake
its a seldom occurring but every once in a while I will get a p0157 code , sometimes also 0137 but not as frequently.
These always show up with my p0131/0151 codes, might be worn out primary o2 sensors; may be an air/fuel issue also.
edit- now I see why I was confused, your original post says to forget about disabling secondary o2’s but then later mentions to disable them. Which one did you do?
you have to disable them in Xentry
if you don't, the anti pollution part will auto-correct your engine based on the 2 CO sensors you put in the tube
Line 239 NOT present Motor-Code E/A 1, LS-hinter KAT - Diagnose aus
Line 265 OFF Funktions-Code, Lambda-Reg., tv-Zeiten Index 1 aus
Line 301 NOT assigned Abgas-Getriebe-Schaltpunkt Matrix nicht belegt
Thanks man, I was about to head to my friend with Star soon anyways. Can’t believe I forgot to consider this when we were sorting out my tcu tune a couple weeks ago
just a warning, the programming tips in this thread apply to v12 models. If I remember correctly, there was only one line in Star that is related to disabling secondary o2’s for the v8 models on Me2.8 motor software. In this thread there seems to be three different things that were altered
luckily my friend was fluent enough in Star to find the v8 equivalent of these program changes and we were able to disable enough things that I no longer get any check engine lights, no p0131, p0137, p0151 p0157 codes anymore.
I still have a bit of a stinky exhaust under full throttle and I’ve noticed my long term fuel trims are super low in the negatives on a live data scanner. I attribute this to my fuel system issues I’ve been sorting out recently and also the fact I have a Cl55 engine in my CL500 with stock CL500 ecu maps
Some guy online is saying if you “unlock the ecu, then disable the o2 sensors while they are unplugged” then there is no need to leave the o2 sensors in the system.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
CAT delete
