528i's got an O2 problem

[amancuso]

Has anyone had any experience with a code 216 : "Signal Lambda probe after-Kat Bank 2 not any signal"?

Does this mean that one of my sensors has finally gone kaput after almost 150,000 miles? I reset the code 2 days ago, and it returned today.

Many thanks in advance.

[edjack]

That would be my guess. If you change the post-cat sensors, and the code comes back, it's likely that your cats are shot.

Have you ever changed the pre-cat sensors?

[amancuso]

That would be my guess. If you change the post-cat sensors, and the code comes back, it's likely that your cats are shot.

Have you ever changed the pre-cat sensors?

Nope, they are all (4) original.

[geargrinder]

Yep that's a pretty straight up code for "no signal", don't think there's anything surprising there. Should be easy fix. Thats an emissions related failure so depending on your state it would normally be automatic fail...

[amancuso]

Yep that's a pretty straight up code for "no signal", don't think there's anything surprising there. Should be easy fix. Thats an emissions related failure so depending on your state it would normally be automatic fail...

Yeah it is an automatic fail. I reset the code though and went through emissions, it passed. LOL. I think I'm just going to change the 2 post cat ones, and in a few months do the pre cat ones.

[Ed CT]

Yeah it is an automatic fail. I reset the code though and went through emissions, it passed. LOL. I think I'm just going to change the 2 post cat ones, and in a few months do the pre cat ones.

You might want to change both pre-cat O2s first, as they are the ones that are in the feedback loop for engine performance. Running worn out pre-cat O2s may lead to a richer mix and wear out the cats prematurely. The two post-cat O2s are only there to report.

[philly98540]

I'd do them all at once at that mileage. Reset adaptations.

[amancuso]

There's absolutely no DIYs on this for the 99-00 528i post cat sensors. I hope it's not as heinous as what I see for the e46s. Can anyone steer me in the right direction? The pre cat ones are easy enough, but no info on the post cats!

[geargrinder]

Errrm one of the most self explanatory jobs really... It's basically 'Wrench them off, which will suck" then "work the wire out back to the connector, and unplug...".

Definitely wrenching them off WILL suck by the way, if they are the originals.

However... tips:
1. soak in penetrating juice overnight/over days (try soaking, then running the car a very short time to just warm them up and get it to soak in more, then repeat... not too hot so it burns the oil off but warm enough to encourage soaking-in. you might repeat that a couple of cycles / overnight)
2. be REALLY careful on your first try and have good O2 sensor wrench for it, if they strip the heads it will suck more.
3. have a propane torch handy to heat them up if that doesn't work
4. be gentle w/ the connectors, the plastic latching clips are likely all heat-fatigued also, with luck they don't break when you pop them off, but...

There are a couple styles of "O2 sensor wrenches". The 'full deep socket with a cutout' is great but sometimes there isn't clearance for it. No idea about the M52TU. There's also the "crowsfoot-ring-with-a-slot" style which tends to fit in tighter places.

Here's a Pelican DIY, if you didn't find this already. They warn about silicone penetrating oil, I'm not so sure I'd fret that too much as long as you dont get a crapload inside the exhaust and don't touch the new sensor tips to any of it (for instance, you could hose down the penetrating oil with brakeclean before you get near the bungs with the clean new shiny ones).

https://www.pelicanparts.com/BMW/tec...eplacement.htm

[amancuso]

Thanks for the tips. I was just wondering where the connectors were. Probably have to snake them up to behind the engine, which I'm not looking forward to. The car was an SC car all it's life so hopefully lack of road salts helped keep the undercarriage clean.

[geargrinder]

I dunno for your car, but on the E46 they aren't bad. They are tucked into various wiring retaining fittings under the car, pretty obvious, the pigtail on the new one will show you that its gonna be close by.

Now on my M3 I had to relocate the post-cats when I changed the cat config to further back under the car, so I had to indeed slice the harness wrap back and pull down more length, but, in your case none of that will be the case... should be easy.

[pshovest]

........I was just wondering where the connectors were.......

The Pelican DIY is for '97-98's. I believe they're near the fuel rail above the intake manifold for the newer models.

[amancuso]

The Pelican DIY is for '97-98's. I believe they're near the fuel rail above the intake manifold for the newer models.

Yeah that DIY doesn't help 99-03 owners.

[sleuth255]

Full deep socket works best on the pre-cat sensors but you'll need the offset wrench version for the post cats. For each post cat sensor, I cut the cable at the sensor itself then used it as a fish to pull the new cable up (also makes it easier to remove the sensor and you can't mix up connector locations on the top of the engine either). You will need to disconnect the cables from brackets that are easy to see/reach once you're under the car. The brackets may be corroded and need replacing also.

[computiNATEor]

Yeah that DIY doesn't help 99-03 owners.

https://www.bimmerforums.com/forum/s...sensor-removal

[amancuso]

https://www.bimmerforums.com/forum/s...sensor-removal

[Mike WW]

I have done both early and late, both pre and post, I6's with a combo end wrench. But I'm nuts. For late, pre cat sensors you really should use one of the crows foot flare nut sockets. For lack of a better term. I even bought one for the second time.

[geargrinder]

crows foot flare nut sockets. For lack of a better term

That is a perfect term for those! That's exactly what they are...

[amancuso]

I bought the crows foot, but not flare? Is that the one that wiggles around on the end of the extension? Oh and I was able to grab a snapshot of the O2(s)

[geargrinder]

No, 'flare' means it goes beyond 180 degrees, and only has a small slot in one 'facet' of the wrench. A traditional 'open ended' wrench is missing 2 facets of the wrench, a flare nut only has a small slot in one facet. A flare nut wrench lets you slip it over a wire or tube, but still get a grip on all the corners of the nut... FAR less likely to strip the corners of the head. Used most often for brake lines.



The GOOD crow's foot O2 wrench is indeed, both a Crow's Foot (extends out off of the ratchet point, instead of rotating around it) AND a Flare (grips all corners, small slot in one face to slip over the wire).

[amancuso]

Cool then. This is what I bought, should be delivered today.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Also installed lift yesterday... Good times ahead.

[geargrinder]

NICE! I hate people who have lifts.

[andrewwynn]

NICE! I hate people who have lifts.

Until you befriend them!


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