Good... now I know what is the CPS and where is it.. Thanks GREG...

than, can I replace it by myself? how can I stretch my arms and tools together into the little space to perform the replacement? Is the original CPS made by BOSCHE?

thanks for reply

 

C'mon Karl, you are about half the size of Greg. If he can get to it, you better beware that you don't fall in.

 

Use the hood release

as instructed and take your belt off and cover the fender with a blanket and dive in.
Watch the sharp heat shield
You will get at it:thumbsup:
look at it for a bit and absorb how it all fits and then when your view gets obstructed your memory will guide your hand motor functions.
:bowdown:

 

Nice PDF Greg, thanks.

 

'97 E420 O2 sensor location

I need help determining the location of the O2 sensor(s) in my '97 E420. The DIY is for a the V6. Any DIY's for the V8? How many sensors does this model have?

 

o2 sensors

I need help determining the location of the O2 sensor(s) in my '97 E420. The DIY is for a the V6. Any DIY's for the V8? How many sensors does this model have?

I know there's 4 sensors. Exactly where they are...you need to get one of the experts to chime in. Ohlord...a little help, please.

 

a quick question:

How to remove the engine cover???? I saw a picture from the spark plug replacement thread and it says that there's a latch near the engine cover but I didn't found where is it..

 

Engine cover

just pops up and off. Little rubber nubbins secure it with pressure fit. Just lift at any corner and be sure when you replace it to secure the little rubber anti vibration strips and the funny shaped rubber flaps along the side of the cover.
:bowdown:

 

got it.. I'll try it later...

what does engine cover use for? can I running my car without the engine cover?? los angeles is hot, so remove the engine cover can let engine stays cooler?

 

Can I get someone to recommend a MB approved anti seize lubricant for O2 sensors that can be purchased at a local auto parts store? Some of the listed products are obscure to find. I bought Permatex lubricant but was told by another moderator that type is not an approved lubricant. I purchased it because Permatex thread sealant was used in the rear differential DIY, so I figured it was good enough for my O2 sensors.

 

Bosch O2 sensors come with anti-seize. Personally I wouldn't buy an unknown brand at the parts store, who knows what you're getting.

Any of the usual Anti-seize products are fine in either a silver or gold color to them. DO NOT BUY ANYTHING THAT HAS SILICONE IN IT, though. And be sure to put the anti-seize on the threads ONLY and not down near the body of the sensor or you'll shorten it's life.

Here's one you can use (and it is Permatex brand, I'm not sure why someone would steer you away from it):

 

Greg,

That is the exact Permatex anti seize lubricant I bought last week! So I don't understand why it was considered unacceptable. At any rate I probably would not have bought anything if I knew the sensors came pre coated already. I'll get my refund.

On a related topic: for my M119, which type of O2 sensor socket works better, the conventional or crow foot?

 

I would bet you would have trouble using the crowfoot on the front ones. There is barely enough clearance as it is, plus that plays with your TQ settings a bit.

For the rear ones use a conventional wrench to get them loose (box end, slide it over the connector) since you can apply torque closer to the plane of the threads. Putting them back just use the socket and TQ wrench.

Re: the anti-seize, I think you created a bit of confusion by referring to it as SEALANT in your other thread. It is everything BUT that. Permatex Anti-Seize lubricant as pictured is just for anti-seize, no reason to use it where you want a sealant.

FWIW, IMHO for the differential plugs you are better served to use teflon tape, since they are pipe (taper) threads.

In any event, open one of your O2 sensors and make sure it is included (mine came with it already on the threads, there was a plastic protector cap on there, use a bit of caution when removing so you don't get any on the sensor body as some will come off with the cap).

 

^^^ Same place as the one you reference in this PDF, it's just on the other bank, visible if you look behind the engine on the passenger side...with the hood all the way up, of course.

 

Thanks for the reply gregs210,

I know I have asked before somewhere but not sure if it was answered,

If I just want replace 2 two of them (saving money), I can just replace the two that's reference on this pdf? These must be pre-cat? And I suppose the two on iluv's picture is post-cat?

 

I know, I know, should replace all four of them. But why do they have to be so darn expensive.

My wallet felt lighter even just thinking about replacing them

 

O2 sensor replacement for M119 engine

My son and I took a shot at replacing O2 sensors on our E420, which has the M119 V8 and limited engine compartment space.
Parts and tools
Bosh OE sensors from AutohausAZ (about $90 each - 4 required, 3 different types based on location)
22mm open end wrench (Sears - $14)
13 mm socket and 13mm wrench
penetrating oil
rubber mallet
Duct tape
Troublelight
Jackstands
Hydraulic Jack

Sequence
Wait 1 hr after parking the car for the CATs and exhaust to cool off.
Safely jack and secure front end of car
Rear O2 sensors are easily accessed underside of car, mid compartment
Slide in from the side of the car for best position
Sensors are perpendicular and horizontal pointing outwards on exhaust banks.
Apply penetrating oil and wait 15 minutes
Remove electrical connection
Place box end of wrench over sensor and remove (use mallet if needed)
Both rear sensors are the same part number.
Replace w/new sensor, careful not to touch or markup sensor tip (anti-sieze lubricant is already on the new sensor)
Tighten securely
Reinsert signal plugs (only goes in one way)

Front O2 sensors are very difficult to reach, and can only be removed from the underside of the car for the M119 engine in a W210 body. (Front ri
Passenger front side has a unique part number)
Slide in from front of the car for best position.
Follow right exhaust bank, upstream of CAT, sensor points up and back next to the starter motor.
Apply penetrating oil and wait 15 minutes (meanwhile, get familiar with how to get both hands up on sensor blindly)
Using the open end of the wrench, insert over sensor as parallel with the CAT as possible, and loosen. (not easy, this requires good hand strength)
Remove sensor
Duct tape the new sensor plug (wire) to the old sensor body (wire)
Have an assistant gently pull up old/new wire wire while guiding past heat sheilds.
Have assistant remove old plug and reinstall new plug.
Twist the new sensor 8 full rotations counterclockwise
Remove new sensor protective cover and thread into place (blind fit) and now the need for pre-twisting the new sensor wire become evident.
Use wrench to tighten.
Take a break or a beer, you will be tired at this point.

Driver's side front additional instructions:
This o2 sensor also has unique part number
There is a heat shield over the steering knuckle that needs to be removed to provide access for your hands. Use 13 mm wrench and socket combo. The cage assembly is light aluminum, with the 2 halfs held together at the top with 2 foldling metal interlocking tabs.

(Full disclosure, I did not have the finger strength to break the torque on the last sensor. Also tried to insert a special o2 sensor socket, there was not enough room to apply. Since I am a stubborn SOG, am looking for a longer wrench or some other mechanical advantage and will retry later. It can be done without having to drop the exhaust pipe. More to follow)

Prior to dropping the car to the ground, start the engine to ensure that it does not rough idle. (Open garage door)

Merry Christmas and Happy New Year to all.

 

very nice

hey just changed the cps on e430, took me like 20 minutes to do it, great help from this thread, thanks greg !!!!:thumbsup: save me some good $$ by doing it myself..by the way car is running great..thanks again

 

Where can I find the CPS in my 96 E320 i6? My engine looks different than the one in the PDF or the other CPS topic.

 

These pics may help.

 

Damn. First the new CPS was wrong. My has only 1 connector, not 2.
Then, I changed it (with the only one they had on stock), which looks identical to the old one, but when putting that in, the car wont start at all. Putting the old back, car start right away. Again the new one, nothing, wont start.
Is there something else which has to be done after replacing the sensor? Or might the sensor be defective?

 

I am a newbie here and I know a little bit about fixing my car with DIY. Could someone please help me or point me to the direction where I could get info on how to replace an O2 sensor heater circuit bank 2 sensor 2.
thank you very much for your help.

 

The heater circuit is part of the O2 sensor. If you're over 100K miles replace them all, B2S2 is driver's side underneath sort of later to the front of the transmission pan. Use the search function and you'll find lots of information.

Please click user cp and complete your profile.

 

Thank you Greg. My car is a 00 E320 and it has 93k mi. and the check engine light has been on and off intermittently. I will do more research on how to replace them all and if I could do it myself, I will replace them all. Again thanks.

 

The driver side pre cat O2 sensor has very limit space to work with. The only O2 sensor socket worked for me is Performance Tool W1267. It has a wide slot opening that can fit Bosch wires. The only approach is from top to access the sensor.

Autohausaz listed same O2 sensor for both side. Being caucious, I only ordered one. It confirmed that it is too short for the passenger side. It has identical length to the driver side O2 sensor, so it was installed to the driver side. Importec listed two different parts for two side. It is more expensive than autohausaz. Hopefully, it will have correct length, will find out next week when I get it.

 

autohausaz price is too much for direct fit Bosch O2 sensor. For my car, it's $140 for the front (upstream).
If you can cut/trim/push/plug wires, advanceautoparts.com sells the Bosch premium universal front sensor for $68. It comes with their patented Smartlink. Basically, you measure the original wire length the follow the direction to cut/trim/push/plug. There's also coupon to sweeten the price.
# $5 off $15+ with code BIG5
# $25 off $60+ with code BIG25
# $30 off $75+ with code BIG30
# $35 off $85+ with code BIG35
# $50 off $200+ with code BIG50
# 20% off Sitewide with code P20
Register with ebates.com to get 4% cash back, too, when you click to go to advanceautoparts from ebates.com
Effectively, you get 2 sensors for real cheap, less than the price for 1 direct fit at autohaus.
Buy 2 for $136 (2 x $68), use coupon BIG35 to get $35 off. ebates.com gives back 4% of 134, enough for about 1.5 gallons of premium unleaded gas. Net cost for 2 is $94.

 

I thought I saw some post somewhere suggesting not to go with those universals. I followed those suggestions becasue I don't want to have complications.

 

It's OK to spend money to buy peace of mind.
It's Bosch brand. I put two universal front sensors in my '01 E430 4000 miles ago. I also put one universal rear in my 99 E430 30K+ miles ago.
Cut/trim/push/plug takes some work.

 

I guess you're right. They are identical ones as the pre made ones.

There are two kinds though. One is "planar", the other is "heated". I think the heated kind is what we need. They are more expensive though, $93.00. Planar type is $66.00.

So, by buying pre-made ones, I spent about $100 extra for two sensors. (without coupons)

Oh well, I'll make sure the problem is fixed with the pre-made ones first. Then I'll play with the universal type and experiment with it.

Thanks for the coupon information. I will definitly look into that next time when I purchase.

 

I've done about 25K miles with the universals. They are exactly the same are the pre-made sensors, except that they don't have the plug fitted. Fitting the plug takes about 15 minutes even if you are like me. By that I mean I measure it, re-measure it, agonize whether the measurements are really correct and whether the instructions weren't screwed up, etc, etc, and then finally take a deep breath and make the cut.

It literally was a snap after that the make the connection.

Although I must admit that I did cut the wires about an inch to long - since it is easier to trim the wires again after a test fit, than to add a splice.