[Gerin10019]

So I drove the car about 100 miles, light came on again. Didn’t check the code yet but assume it’s the same cat bank 1 code. Will check tomorrow or may make an appointment at the dealer.

My ? Is replace the cat, try all o2 sensors first, take to dealer/ professional who knows bmw not from YouTube, or ditch the car?


I’ve done the work myself, it’s a second car. I’m convinced I can fix anything via this forum and YouTube but perhaps I’m in too deep. My husband wants me to ditch the car. I have no mechanical background, besides rebuilding a Volvo/ Penta inboard Diesel engine from a sailboat as a kid. It sunk in a hurricane, was bought back from the insurance company. Took all winter and a ton of trips to the library. No YouTube or internet back then. But I fixed it. Also tinkered with a mgb as a kid.

So part of me wants to throw in the towel part of me wants to see it through.
Bought this as a back up car to my db9, for winter and bad weather days.
Husband would prefer I get rid of it. I’m a Doctor by profession and semi retired now. I like a challenge but...

Back story.


08 335xi bought used from original owner, 97,000 miles
Car had turbos replaced at 93k had some sort of 100k mil warranty always dealer maintenance

Car was perfect besides tire sensors until about 102k miles
Then car started with cold start miss, most of the time it would go away on its own, or turning it off on would fix
Check engine light went on
Replaced plugs, coils, cabin filter and air filter. Car still had a miss, replaced hpfp. Car drove better but still not right and check engine light went on.
Replaced all injectors with index 9. Car drove great. At this time changed the valve cover gasket, oil filter housing gasket, oil change with liquid molly and coolant flush.

Last week had a coolant leak after using the heat for the first time. Replaced 3 hoses. Coolant pretty much everywhere

Check engine light on again. Bank 1 cat converter

Car is driving great still, I cleared the code drove 55 miles it’s still off

I’m not inclined to replace the cat yet, but of code comes back should I replaced o2 sensors or replace the cat?

Any help or suggestions appreciated

Thanks.

Julia

[Gerin10019]

So far the only harm I’ve caused is to my finger and I’m not even sure what I burned it on. I hope I posted that correctly. If not it’s in my album

https://www.e90post.com/forums/pictu...ictureid=71954

[Tambohamilton]

It'd be simpler if you posted this as a reply in one of your other threads, but never mind.

What is the actual code you're seeing? Any further data? What driving conditions caused the code (WOT, cruising, etc)?

Sounds there has been a lot of work done on the car, and it also seems mechanically good, so it'd be a shame to give up on it at this stage. Electrical problems are the most frustrating, but often simple fixes. I say bear with it, you'll get there!

If you're really frustrated and just want it to work, take it to a pro with a good reputation. I don't see any reason why you can't fix it yourself though, so long as you've got tools, time, space...and patience.

[Gerin10019]

https://www.e90post.com/forums/pictu...ictureid=71955

[Prabuzz]

Originally Posted by Tambohamilton

It'd be simpler if you posted this as a reply in one of your other threads, but never mind.

What is the actual code you're seeing? Any further data? What driving conditions caused the code (WOT, cruising, etc)?

Sounds there has been a lot of work done on the car, and it also seems mechanically good, so it'd be a shame to give up on it at this stage. Electrical problems are the most frustrating, but often simple fixes. I say bear with it, you'll get there!

If you're really frustrated and just want it to work, take it to a pro with a good reputation. I don't see any reason why you can't fix it yourself though, so long as you've got tools, time, space...and patience.

+1

[mainbearing]

You can try an IR thermometer to check the temperatures on both cats. They should be about the same.

I would think if Cat 1 is running cooler then it might be bad. If they are running the same temps maybe change out the downstream #1 sensor first.

Is the engine using oil? How is the MPG? Maybe Bank 1 cylinders are somehow damaging the cat? Maybe pull the plugs and inspect? Do a compression check?

[weehe126]

Did you code the injectors?

Normally a cat will clog when it goes bad. That normally happens when a lot of oil gets to it. It would also cause low boost/high wgdc issues on one bank. I am guessing the O2 sensor is bad. I can't remember is they are the same connector, but one way to test would be to swap the second O2 sensors bank 1 or 2 and see if the code moves with it.

[Gerin10019]

I did not Code the injectors, dealer told me they did not need to be coded.

The ses light was on the first time I drove it today about 15 miles doing errands
Came home, car sat for about 5 hours. Started car and heard a tinny almost like a loose heat shield noise, went away in about 30-40 seconds. I assume it’s the cat. Car is driving fine. Fuel economy is about the same As it was when I originally bought it. Went back up after new coils plugs and injectors

Drove about 3 miles made a quick stop at Whole Foods, no noise upon start up and ses light went out. Went to my dinner drove about 15 more miles light is still out.

If it’s an o2 sensor would the ses go on off?
Swapping out the sensors seems like a reasonable thing to do. I did order two new o2 sensors they will be in Tuesday.
Sadly I’m inclined to think it’s a clogged cat. I took a welding class a few years ago, a fabricator I know so I’m able to have someone help me weld in a universal cat but not sure I want to do that quite yet.

No evidence that I’m burning any oil.

[gbalthrop]

STILL awaiting CODES. NOT Mercedes, NOT Aston Martin; BMW Fault Codes, otherwise known as DIAGNOSTIC Trouble Codes (DTC's). We can handle either P-codes or Hex Codes, and if you don't have a Scan Tool, any Advance Auto or Autozone can provide them FREE. Might even provide Freeze Frame Data and Fault Details, with Mileage/km when each code saved, and current mileage.

Indicated Diagnostic test results should ALWAYS be obtained & evaluated before rendering a Diagnosis or Prognosis, RIGHT "DOC"?

George

[mainbearing]

Isn't the code P0420 in post #4 picture link above?

If the substrate has disintegrated and making the loose stone sound, then I would think the converter needs to be replaced. Then install new oxygen sensors along with it.

[Tambohamilton]

Originally Posted by gbalthrop

STILL awaiting CODES. NOT Mercedes, NOT Aston Martin; BMW Fault Codes, otherwise known as DIAGNOSTIC Trouble Codes (DTC's). We can handle either P-codes or Hex Codes, and if you don't have a Scan Tool, any Advance Auto or Autozone can provide them FREE. Might even provide Freeze Frame Data and Fault Details, with Mileage/km when each code saved, and current mileage.

Indicated Diagnostic test results should ALWAYS be obtained & evaluated before rendering a Diagnosis or Prognosis, RIGHT "DOC"?

George

P0420 from the post above.

OP, it sounds to me like it's a bad cat, and potentially bad lambda sensor(s). I'd start by swapping over the lambda sensor from bank 1 to bank 2, then clear codes and drive. That way you know that if the code comes up for the same bank, it's the cat that's bad, or if it moves to the other bank it's the sensor that's bad.

[Gerin10019]

Hi everyone thanks for the input.
I can scan for further diagnostics today
I’ll keep you posted.

For now my question is. If it was a bad sensor would the light clear itself?
Seems more reasonable to me that if the clog perhaps freed itself temporarily that would clear the light. I guess what I want yo know is a sensor like a light bulb it works or doesn’t? Or can it sometimes work?
I’ll also swap the sensor suggested.
My other ? Are if I determine it’s the cats...
After market ok if California emmisions?
Replace both of them?
Worth doing all 4 02 sensors at the same time?

My husband gave me a month to reasonably figure this out.
If I can’t fix it myself I’m going to donate the car. I promised no used used care again
He is not very handy and doesn’t realize my satisfaction when I can fix it myself. He would prefer I just take it to the dealer like “normal people”
But after 26 years of marriage he knows by now I’m not Normal

I’m considering taking it to a shop for confirmation but maybe do the work myself

Thanks again for any all suggestions

Julia

[Tambohamilton]

Lambda sensors can sometimes work properly, and sometimes not, when they're dying. In fact, many sensors will do that.

I think you can get this sorted well within a month, even if you need to take it to a shop for diagnosis.

Good luck!

[weehe126]

There are no injectors that do not need to be coded....

[banglenot]

Hi, Gerin.

Highly recommend you pick up a Foxwell NT510 or 520, with the BMW software installed. Should be about $150 or less. I bought it for my wife since she's at the summer place when I'm not.

There are better, but this is the best compromise among a complete BMW software set, price, simplicity for people who don't want to fiddle with phone apps or PC apps, and useful embedded tools. Plug in and go. You'll be amazed what it can tell you versus a non-BMW code reader. Seriously, to fix a BMW you must have access to BMW codes and routines. I use ISTA, INPA, Carly and Protools -- but the Foxwell is the go-to for the first diagnostics.

I really resonate with your desire to DIY. Though sometimes frustrating, each problem is a puzzle that's very satisfying to solve. And wrenching is very relaxing overall. Even throwing a part across the room is cathartic....

Good luck.

[MightyMouseTech]

Best way to diagnose a cat is to pull the primary O2 sensors and run a borescope down the holes. Look for any damage to the catalyst. Should be a nice, perfect grid. Any damage seen means replacing the cats.

Seems that almost all new injectors are 215 calibration. If they are the same as the old ones removed, you don't need to code them. But you have to make sure the old and new are all exactly the same.

A borescope comes in handy here as well, read the injector codes and compare to what is stored in the DME.

[Gerin10019]

My old injectors were index 9

Does everyone suggest to replace both cats if that is what is determined wrong or just do one?

Thanks

[arkie6]

Where did you buy index 9 injectors? Used injectors? Regardless if both the old injectors and replacement injectors were index 9, each replacement injector will have a specific flow rate and energy value marked on it that needs to be programed into the computer so that the computer can properly control the fuel flow into the two banks of cylinders. If all of your injectors are marked with the same flow and energy value, then you likely have counterfeit injectors. There is no way that new OEM injectors will all have the exact same flow and energy values.

[Gerin10019]

The Injectors were new not used.
They were oem Siemens. I doubt they were fake.

It seems to me like coding info on the injectors needing to be coded
Some say yes some say no. Including the dealer.
I’m really at a loss at this point.

The 02 sensors are functioning properly but I did order 4 new ones seems prudent at 105k miles

Now I need to determine if I should replace both cats with oem or aftermarket is sufficient
Also should I do one or two.

Is it possible the of the injectors do need coding I inadvertently caused dame to the cat?

[Tambohamilton]

You should at least check the injector codes vs the stored codes. The chances are they do need to be coded; the code is a calibration value, which is necessary to achieve accurate fuelling. It's super easy to do using bimmergeeks protool...it's less easy but much cheaper to use inpa. There are plenty other options too. Bottom line is that coding is almost certainly necessary.

Incorrect injector codes could result in damaged cats, yes. They could cause the engine to run too lean, and subsequently overheat the cats.

I'm sure OEM cats would be the safest option in terms of guaranteeing correct fit and function. But maybe there are aftermarket options which are well tested...sorry, I don't know any more about that.

[Gerin10019]

How do I check the injector codes vs stored codes?

[clegg]

The injectors have a 3 digit number and another set of 3 digits below the first set of digits imprinted on them. Like this:

571
231

You will need Inpa or some form of scanner to see what the set values are coded to for the DME.
They will all be slightly different.