A what tf! 5 codes and no symptoms to show for it

[spyderg0d]

Ive been going through the 03 325i for about a year now, fixing all issues trying to get the cel off for this years inspection and its been a rollercoaster for sure.
New converters
New intake gaskets
New intake hoses and o rings
New starter
New altinator
New rad, pipes, hoses and o rings
I confirm all the 02 sensors are working with live data reading scanner and the monitor sets
Last week i changed the intake camshaft sensor as it suddenly went / created a code, and had no reading whatso ever with a meter.
I cleaned the icv and cvv
Checked disa valve

The cel came on about 70 miles after resetting codes and driving on the highway. I probably put too much throttle in it as i read your supposed to keep it under 2.5 or 3k until all the monitors set. I read the codes today and found 5 codes. 3340 0171 0174 2240 and 2237 that werent there before besides the camshaft code. Which after seeing the live data and seeing the 02 sensors work, and knowing the camshaft sensor a is brand new, makes me suspect an electrical problem. Correct? Anyone have any guess for me?

[spyderg0d]

As of now, im reset codes in a attempt to keep it under 3k until i see all the monitors set.
I forgot to mention all the monitors were set except the catalyst, which was set before when i only had the camshaft sensor code. So it only adds to the confusion.

[dhurley34]

Is the new cam sensor aftermarket or OEM?

[spyderg0d]

Oem.

[Muzz258]

With a warm engine at idle, what are your short term fuel trims? >8% show a vacuum leak.

[spyderg0d]

I guess il search for vacuum leaks again.

[spyderg0d]

I didnt find any vacuum leaks spraying around with maf and tb cleaner. I took some screenshots of the live data at idle and at 2k. Screenshot_2019-05-03-11-48-23.jpgScreenshot_2019-05-03-11-49-23.jpgScreenshot_2019-05-03-11-49-37.jpg

[spyderg0d]

I cant find any data on what the maf on a 2.5l is supposed to be at idle. Isnt mine kinda low for alittle under 700rpm?

[spyderg0d]

After staring at the live data, while the car is warm and at idle, i see the stft 1 and 2 are both always between -8% and 7%.. Yet my ltft 1 stays from 22% to 25.5% and ltft stays from 23.5% to 26.4%. What would keep my long term fuel trims so high even though my stft are in proper ranges?

[spyderg0d]

When going to tear the intake off looking for a leak, i found the vacuum line from the intake boot that runs to the fuel filter had come off by the filter.
Luckily i had some vacuum line from another e36 i have, and fit it.
Now my ltft are averaging 12% to 20% with occasional jumps to 22% while decelerating. So i think i should be fine as far as i know. But that does imply i have another leak somewhere else as well? What are regular ltft?

[whiskychaser]

The line to the fuel filter is not actually a vacuum line. It is a sort of fuel overflow. But it will let air in so well spotted anyway IIRC, the highest LTFT you can have before the ECU starts complaining and turning on the SES light is 11.
I think that is the point where it refuses to chuck any more fuel in and says you are on your own now, pal. The lower they are the better but I think 3 or 4 is a reasonable target.

My SES light comes on at 12 and the LTFTs never get higher than that. My understanding is that if your STFTs are high at idle but go down when you rev the engine, it indicates a vacuum leak. That is because the proportion of unmetered air is quite large at idle but less so with the throttle open. FWIW, my STFTs are 0.13ms (bank 1) and 0.14ms (bank 2) and never seem to move from that.

[Muzz258]

Your LTFT's are telling you that the engine is running lean all the time. Try smoke testing it.

[spyderg0d]

Strange, ive never had the ses light come on after i replaced a shorted icv a few years ago. And in the last year i havent had the ses light on at all, only the cel.
I guess i will have to try smoke testing.
But first, how long does it take for the ltft to possibly lower and settle? Ive literally driven the car maybe 2 miles since the hse fix and found the values lower.
I read that the cel only stores a code after the ltft goes above 25% so im confused by whiskeychaser saying 11. Does he mean 11%?

[harrier]

The line to the fuel filter is not a vacuum line. I believe it is reference atmospheric pressure.

As for the rest.

The codes reflect a set of maintenance issues that are very common for an e46 at this age. Your fuel trims are extremely high.

LTFTs are long term adaptations to the fuel/air mixture. The computer reads air inflow via the MAF then the oxygen levels via the precat sensor and determines whether to add (if lean) or remove (if rich) fuel to achieve the right mix. STFT are basically real time trim to adapt to immediate conditions and LTFT evolve over time from the short term adaptations.

Get OBDFusion and a Bluetooth OBD adaptor. Read the codes - you will likely have p0171/0174 and potentially p0304/0305.

You get 0171/4 when your fuel trims are over 10%, but understand that spec is +/- 2%. What this means is that most folks at this point have out of spec fuel/air even if they don't have a check engine light or code. At 20+% you are off the reservation and likely have many (solvable) issues.

If you have these codes, the greatest likelihood is that more than one of these issues is present (all of this is covered in Jfoj's Post on e46fanatics - Read it). Here are the most common causes:

1. Computer is asking for fuel but not getting it - old fuel filter (60k maintenance interval), failing fuel pump (120k is when some pumps go, some seem to last much longer). Computer sees "lean" mix at precat o2 sensors and demands more fuel.

2. Unmetered air is changing the mix due to vacuum leaks - the MAF measures the air, then the computer adds fuel to get the mix right. If air is entering after the MAF it is unmeasured, and the system gets confused because the o2 sensors are saying there is too much oxygen relative to fuel. Smoke test then replace all rubber bits including vacuum lines and caps behind manifold, boots, and all CCV parts if original. Remove and inspect DISA (if it is not hard to remove either replace the unit or dig out and replace the seal). Consider replacing brake booster (won't show on smoke test). Leaks will tend to have a more pronounced effect at low rpm when the air introduced through the leak is a higher percentage of overall air flow.

3. Sensors are getting old and sleepy and under-reporting. Precat O2 sensors have 100k maintenance interval per Bosch. As they wear they will under-report. This will not necessarily trigger an o2 sensor code, but the lack of a code doesn't mean your o2 sensors are healthy. The MAF can also get tired and misread air flow. If the fuel trim issue still occurs at high rpm it is more likely a sensor issue. Frankly, it is almost always part of the problem, so I would replace with an OE unit only (not eBay, not used) after 120k when you get actual lean codes. Cleaning the MAF doesn’t do anything on these cars.

Lots of folks say these sensors don't have to be replaced ever or at least until they go kaput, but folks also say that if there are no codes there is no problem - high LTFTs are suboptimal even if they don't reach the 10% or more required to trigger the code.

There are more obscure causes, for example it is not rare that someone replaces the precat sensors and swaps the wires for the two banks by accident. Easy to happen, simple to diagnose and will definitely trigger codes.

[whiskychaser]

I read that the cel only stores a code after the ltft goes above 25% so im confused by whiskeychaser saying 11. Does he mean 11%?

TBF, I have a 330i not a 325i but I would have thought the parameters were very similar.

I use DIS which shows the STFT in ms (injector opening times) and LTFT in percentage. The STFT range is -0.35 to 0.35ms and LTFT is -7 to 11%.

[spyderg0d]

Thanks for the clarification. But im not new to auto mechanics, just pretty new to useing proper data. I know its 2019 but ive magically still only had obd1 vehicles and havent had to get this in depth in a car to fix until now. Even after having this car for over 5 years. But within the past year or so,.
New cats, new crank and cam sensors
New disa. New cvv hoses.
New 02 sensors
Unfortunatly a used fuel pump and unit
New intake gasket, new o rings for the new hoses that got stiff and didnt look good when i was searching for intake leaks,. I used very small amounts of rtv on disa, and other intake componants. I was posative i didnt have any intake leaks. But, il check for the 3rd time. After wife gets out of work this afternoon il do a thorough tear down inspection and bullet proof it all again. The only thing i might have suspicion of is the cvv. I get a bit of cold weather condensation and minute amounts of the milk film because of short drives.

[spyderg0d]

Reasons for replaceing. I had catalyst codes, the 02 sensor removel resulted in cone falling out of 1 cat. So i replaced cats with 02 sensors. Ongoing cam sensor and misfire codes led to replaced cam and crank sensors. Hearing the intake noise and rattle led me to a broken disa flap, and replaced. In the winter in several days of below 20 degrees, the cvv would freeze and result in massive smoke from the car, replaced cvv and hoses with winter package grade. That solved the freesing but i still get a bit of milk accumilation at the oil cap, and the cvv run down hose. The milk goes away when driven in warmer days and im 100% its not a hg issue, as i have no coolant loss after i updated that system and no mixing. (The engine in the car i went through maybe 5 years ago with new gaskets and the sort, car has never been even close to over heated).

[spyderg0d]

Went through the intake again. Found a cracked lower boot. 3 missing caps on the backside of the manifold. I made caps and siliconed the cracks. Ended up stripping the front intake stud in the head. I ripped the coolant temp plug off the wires and it took time to pull the pins and reconnect the wires.. What a mess that was. So now i have absolutely no intake leaks.. Ltft are still between 16 and 20. Made no change.

[spyderg0d]

Ordered new intake boots.

[spyderg0d]

Now when car is at ot the ltft is at a steady 10.2 .
In about a week the new boots and intake gasket will be in along with real caps and whatnot, il have to tap the boss in the head as well. Il report back after that. Thanks so far guys.

[Honolulu]

I looked at the live screen shots and noticed that with zero throttle, and coolant at 244 degrees (pretty hot?) your idle speed is 2000 rpm. Realize by now you've attended to several vacuum leaks, but high idle with no throttle is a sign of a leak. You may still have one or more if your idle is still high without any throttle.

I'm also trying to get into reading live data on my BMW bike, which is non-op just now.

[spyderg0d]

Nah, for some reason that widget doesn't update the rpm very fast. If i make a rpm widget all on its own it keeps up.
I havent put the mechanical fan back on the car yet, and it was sitting at idle still.
Its back on now though. I take it off in winter as it doeant allow the heater to get warm in any descent amount of time when its -25f for weeks on end.

[spyderg0d]

Also, after the last run through and cobbing every leak i found, the idle went down to 550 to 600. And my ltft stay under 10.2. But indeed if its suppsoed to be around 3%, im still missing a descent vacuum leak somewhere. Which still bugs me. Il have to silicone the icv in, the hoses on the bottom of the intake, and possibly the throttle body. Ha. If i dont take care of the vacuum leaks for good, im gonna sell this car. Better now thwn after all the new parts aremt worth anything as a sales piont. 150k. New almost everything. Haha. What you guys think its worth? Has clear coat peel, everything else is just used amd not bad.

[harrier]

TBF, I have a 330i not a 325i but I would have thought the parameters were very similar.

I use DIS which shows the STFT in ms (injector opening times) and LTFT in percentage. The STFT range is -0.35 to 0.35ms and LTFT is -7 to 11%.

Lean code at 10%

[harrier]

Also, after the last run through and cobbing every leak i found, the idle went down to 550 to 600. And my ltft stay under 10.2. But indeed if its suppsoed to be around 3%, im still missing a descent vacuum leak somewhere. Which still bugs me. Il have to silicone the icv in, the hoses on the bottom of the intake, and possibly the throttle body. Ha. If i dont take care of the vacuum leaks for good, im gonna sell this car. Better now thwn after all the new parts aremt worth anything as a sales piont. 150k. New almost everything. Haha. What you guys think its worth? Has clear coat peel, everything else is just used amd not bad.

You have to smoke test. Don’t use RTV, it is a hack solution. You have to replace the CVV and the various hoses for the SAP.

Spraying fluid will avail nothing. Many leaks are low or inaccessible. You have to smoke test.

As I mentioned before, the fact that your o2 sensors are reporting does not mean they are not the problem, same with MAF. O2 sensors have a 100k replacement interval. If they start soft failing they can trigger lean condition.

Also check the fuel pump and filter. Filter is 69,000 mile maintenance interval. Poor fuel supply will cause lean codes.