420SEL O2 Sensor Wire Location - PeachParts Mercedes-Benz Forum

wbain5280 · #1 10-06-2006, 12:37 PM

I've looked at the DIY article in the DIY section http://www.peachparts.com/Wikka/M103VacuumLeak but I cannot figure out where the wires are? Any help would be appreciated, pix, verbal etc.

wbain5280 · #2 10-06-2006, 01:12 PM

OK, I found it. The wires are behind the front foot panel on the lower left hand side. I checked the signal and it's a really low value or no value,so now I've got my local parts guy checking his older 3 wire O2 sensor supply.

wbain5280 · #3 10-11-2006, 12:24 AM

I bought a Denso generic three wire sensor on Tuesday and tried to get the old one out. It would not budge. I'm taking the car to the school on Friday and I'll have a go at it on the lift. My fave instructor says he'll have his class scope the old one for a signal. While I'm there, I'll replace the shifter bushings and do an underbody inspection. I know that the steering leaks but I don;t know where. In the mean time, I'll replace the injector seals and holders and the air bypass tubes. Maybe while I'm there, I can get an emissions check.

I've also got to get the underside cleaned, so I'm taking it to a spray wash place for a bath. The rear seal must be bad.

sixto · #4 10-11-2006, 01:47 AM

For some reason the power steering return lines have a much shorter life than the pressure line. There's a return line from the steering box to the cooling loop, and from the cooling loop to the reservoir. The fitting that screws to the reservoir can also leak.

Sixto
93 300SD

wbain5280 · #5 10-11-2006, 04:02 AM

Thanks, I'll definitly check that when the car is on the lift. When I was poking around looking for the O2 wires, I found a complete PS gear O-ring set under the front seat. I also have lots of low pressure PS hose that I can use to replace the existing hose. Maybe all I need to do is tighten the clamps.

wbain5280 · #6 10-12-2006, 12:12 AM

I took the car down to spray wash the underside. On the way, I witnessed a Ford Mustang GT crash into some fencing after going through a left hand turn too fast. Since I'm a good citizen, I stopped, as did someone else, to assist and call the Police. The guy was charged with reckless driving.

I got to the spray wash place and fed a huge number of quarters into the slot machine. I'm pretty sure I blasted most of greasy crud off the underside of the front chassis and engine. It should be much easier to work on the car on Friday at the car repair class. Shifter bushings, rear tires, change the engine oil (all 8 qts), and the list goes on.

I also cleaned some of the interior panels. They were filthy, it was really disgusting. How can someone let such a beautiful car get so dirty. I really need to replace all the seats as well.

wbain5280 · #7 10-13-2006, 11:50 PM

Tonight, I got the O2 sensor out. I went to the school where I'm taking auto classes and used a 22mm wrench on the O2 sensor body and a 27mm on the open end of the 22mm wrench as an extension. A good soaking with a penetrating spray helped too. It was a real PITA to get out though. Then I soldered the wires and used heat shrinkable tubing to seal it. Eventhough my car passed Va. safety inspection, I really do need a new exhaust system. It's really rusty.

I also replaced one shifter bushing but not the rearmost bushing, though not for lack of trying.

My steering box has a leak so I'm going to swap it out with my other one from my 300SE.

This weekend, the intake seals and vacuum lines etc. I hope to have my emissions test by Wednesday. I have a test Tuesday morning.

wbain5280 · #8 10-19-2006, 12:19 AM

A few days ago, I took the intake manifold out. I used the Pindelski site as a guide. The SLC he did this on is close but not exactly the same. I took lots of pics. It's almost a jigsaw puzzle. The inside bits of the manifold were coated in baked on carbon deposits. I took it, the two halves, to the school. I cleaned them, washed them off and them bead blasted them. The manifold is now nice and clean. Today I removed the EGR pipe from the valve. The end that bolts into the lower manifold was blocked by crud so I cleaned it out. I also found the rubber hose from the back of the left side cam cover to the underside of the air cleaner was also blocked. The car should run a lot better.

Then I went to the dealer and bought plastic emission hose, thermovalves, a check valve and all the little rubber elbows. I had all the old ones bagged seperately and the parts guys appreciated it. They told me they get calls over the phone from people wanting little pieces. They're so vague about what they need.

I'll post some photos soon.

I'll be busy on Saturday, the HMCS Toronto will be in Baltimore for tours.