C-Class (W203) 2001-2007, C160, C180, C200, C220, C230, C240, C270, C280, C300, C320, C230K, C350, Coupe

Does the C230 need the O2 sensors?

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Aug 30, 2006 | 12:53 AM
  #1  
pugguy2001's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2005
Posts: 313
Likes: 0
From: NY
2016 C63s AMG
Does the C230 need the O2 sensors?

Does the 2005 C230 need to have the o2 sensors hooked up for reasons other than emissions. I've heard alot of AMG car using straight pipes inplace of the cats and they had great results. Will the check engine light come on. While the car run properly with out both o2 sensors?

Last edited by pugguy2001; Aug 30, 2006 at 01:56 AM.
Reply
Old Aug 30, 2006 | 01:14 AM
  #2  
Blazinpin0i's Avatar
Senior Member
 
Joined: Jun 2006
Posts: 287
Likes: 0
From: Paramus, NJ
Jeepney
hmmm... i know the 1st o2 sensor on the CAT if removed will throw a check engine light and error codes. I also heard that the 2nd o2 sensor is not connected to the ECU so if removed wont throw any error codes, correct me if i am wrong.
Reply
Old Aug 30, 2006 | 11:36 AM
  #3  
Buellwinkle's Avatar
MBWorld Fanatic!
 
Joined: Nov 2001
Posts: 6,211
Likes: 2
From: Laguna Niguel, CA
You can just use black electrical tape to cover the check engine light and your car will run on a fixed mapping that bypasses the O2 sensors but. You won't see a difference on a dyno because at WOT it bypasses the O2 sensors but you will see it in day to day driving and fuel economy but your probably prepping your car for the track so what's the difference.

In the good ole days they use MIL eliminators (do a google search) and bypass the O2 sensors but I'm sure that will work with the new 5 wire O2 sensors.
Reply
Old Aug 30, 2006 | 01:33 PM
  #4  
pugguy2001's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2005
Posts: 313
Likes: 0
From: NY
2016 C63s AMG
Originally Posted by Buellwinkle
You can just use black electrical tape to cover the check engine light and your car will run on a fixed mapping that bypasses the O2 sensors but. You won't see a difference on a dyno because at WOT it bypasses the O2 sensors but you will see it in day to day driving and fuel economy but your probably prepping your car for the track so what's the difference.

In the good ole days they use MIL eliminators (do a google search) and bypass the O2 sensors but I'm sure that will work with the new 5 wire O2 sensors.
I read they can use the star diagnostic tool to cancel out the check engine light for good? Does this apply to our cars.
To be honest the reason I am asking I brought my car to a race shop by me and had it dynoed. My dynos with the Kleemann mods were nice 205 h/p and 205 torque, at the wheels. I showed them a dyno before kleemann header with the boost kit and a dyno after kleemann header w/high flow cat with the boost kit and since I am a 0-60 person, they asked why did I even go this route. The Kleemann dynos showed how the whole power band shifted. which indeed it did and I know that for a fact, plus the 1/2 boost that was lost. They looked at the stock exhaust manifold and told me it was a stepped header. So he asked me, if i was willing, can he bring make my car back to the 0-60 car it was and even better. So this is why I want to know if our cars need the O2 senors. When you say fuel economy I am guessing I will loss some mpg. Anyway this whole think is just a thought. Thanks for the info
Reply
Old Aug 30, 2006 | 07:56 PM
  #5  
Buellwinkle's Avatar
MBWorld Fanatic!
 
Joined: Nov 2001
Posts: 6,211
Likes: 2
From: Laguna Niguel, CA
What happens when the O2 sensor is removed is the computer has a fixed set of fuel injector mappings to meter fuel that take input from other sensors like the throttle position sensor, rpm, vss to figure out the best guess fuel mix, sort of like the old days of carburators, worked but not very smart. So you take your car to altitude or drive on a hot dry day vs. a humid cool day and the mapping is the same, no way for the ECU to compensate for atmospheric conditions or compensate for a poor performing component like low fuel pressure or dirty injectors because it can't measure if the fuel mix is correct. So the downside is your car will not be as efficient as it can in drivability and fuel economy because it's guessing the fuel injector timing rather than computing it based on need. The O2 sensors are bypassed during ECU open loop mode during startup, warmup and wide open throttle because the O2 sensor is considered inaccurate during those conditions. So what do you have to lose beside fuel economy and drivability? Engine longevity is compromised because you'll run rich and leave carbon deposits or you'll run lean and overheat the cylinder heads and cause pinging. Also it's 100% illegal regardless of if your state has smog inspections, you could be fined by the EPA if someone turns you in, not likely but possible.

So what's the big deal, have the muffler shop drill in holes and weld in bungs to install the O2 sensors. They're not slowing you down.
Reply
Old Aug 30, 2006 | 10:46 PM
  #6  
pugguy2001's Avatar
Thread Starter
Senior Member
 
Joined: Oct 2005
Posts: 313
Likes: 0
From: NY
2016 C63s AMG
[QUOTE=So what's the big deal, have the muffler shop drill in holes and weld in bungs to install the O2 sensors. They're not slowing you down.[/QUOTE]
Ok thanks for the info. I just wanted to know alittle about the O2 sensors so when I go to he shop I can understand what they are going to saying and also I like to put in my $.02, which now alteast I now the deal about the O2 sensors. I dont want to walk into the place blind and not no what to expect.
Thanks Again
So have you been thinking about getting a header. With all of these new headers to choose from you must be tempted.
Reply
Old Aug 30, 2006 | 11:16 PM
  #7  
mig888's Avatar
MBWorld Fanatic!
 
Joined: Apr 2003
Posts: 2,175
Likes: 0
From: Socal
EVE
There are ways to get away with test-piping and including 02 sensors - but I wouldn't abandon them completely - they're good for something .

flip
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 01:46 AM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
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.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE