06 X5 3.0i p0174 p1093

[Optllizer]

BMW X5 2006 3.0i
185000 miles.
Hello, I hope everyone had a great year so far. For past couple weeks I have been trying to get rid of a SES light. At first it was just a P1093 which would pop up intermittently. Basically disappear after couple drive cycles then come back after about 25 miles. I am gonna give a full timeline of what I have done so far.

I first tried to clean the ICV since it needed it and at the same time replaced the lower intake boot. Before installed the ICV again, I did shake it to make sure it moved and well it seemed ok. 25 miles later SES popped up again. Still was p1093.

Next, I checked my MAF using OBDFusion. Fully warm at Idle it was reading 2.6-2.7 g/s. Which is pretty low. I bought a VDO MAF and It came in a continental box. I know that continental owns VDO/VDO is part of continental so I was sure it was OEM. Installed it and MAF was still reading 2.6-2.7 g/s. Drove for 25 miles and SES is back. I decided to return the MAF since the old one seems working and Ive heard mafs last pretty long even past 200k.

Next, I swapped my pre-cat sensors. Bank 1->2 2->1. They are about 25k miles old so they shouldn't be a problem. but still Maybe the pre cat bank 2 sensor was reading wrong. I was hoping it would switch to Bank 1, but now I have p0174. I made sure the o2 sensors were tight, maybe I installed them wrong? I retorqued them and still have p0174 and p1093.

Fuel trim wise, according to OBDFusion, STFT B1 was 2.34%, LTFT B1 was 2.34%. STFT B2 was 25%, LTFT B2 was 1.56% based off my last freeze frame. Engine was at operating temps for this freeze frame.

Today, I pulled in INPA and wanted to monitor fuel trims while going for a quick drive. At idle Bank 1(Lambdaintegrator 1) was sitting at about 0.73 while Bank 2 (Lambdaintegrator 1) was sitting at a static 20.86. While cruising both were -0.50 to 4.84. It seems like the lean problem is only at idle. My latest idea would be that my ICV is bad and while idle its stuck or the computer cant move it.

I would like to point out that my CCV seems like its fine. I did the only cap test and don't have black smoke from the exhaust.

My latest codes from PASoft were
Oxygen Sensor Controller Bank 2 deviation too great deviation rich(lean) this would be p0174.

Misfire Cylinder 4-5-6 misfiring during warm up, worsening emissions

Trimming, oxygen sensor before cat , bank 2, too great in rich range. this would be the p1093

I am currently loss and would like some input. Thank you!

Edit: Got rid of the colors from the codes. The colors were if it was present or now.

P0174 FIXED:New oil cap, brake booster vacuum line was loose and lower intake boot needed to be tightened.

[Effduration]

What do those codes mean?

[Optllizer]

Originally Posted by Effduration

What do those codes mean?

Im just gonna assume me putting the color in the codes confused you, but if not.

P0174 means system is too lean.

The misfires are probably connected to my bank 2 lean problem.

p1093 means that bank 2 is rich but with PASoft, its normally the opposite. so its just the same as p0174 saying that bank 2 is too lean.

[EODguy]

Remember that "P" codes are generic and made for widespread vehicle makes and on my e53 has shown a faulty wheel speed sensor as a faulty brake fluid level sensor....

Sent from Embassy network using Tapatalk

[Effduration]

I agree that the lean condition only at idle is a little perplexing....

I have yet to see any 15-20yr old BMW ( I have 4 of them and have worked on a dozen others) not benefit from a proper smoke test, which includes smoking the brake booster.

[Bdc101]

Since you switched O2 sensors and it didn't follow the sensor, and since bank 1 seems fine (both the trims and not throwing a code), it seems like the only thing left is the injectors - perhaps one of the injectors is throwing way too much fuel in?



One other thing to consider, is where does the secondary air get pumped into the exhaust manifold? I am not sure if there's one point for the whole manifold, or one point for each bank. I'm wondering if it was clogged on bank 2 then, could it throw that code. But if it's misfiring then this is probably not the case.


Also keep in mind that the P0174 is super common for all M54s of this age. It might not be related to your misfire. Just food for thought - not sure if any of this will help

[80stech]

Looks like a vacuum leak affecting bank 2 so check the vacuum plugs at the back of the intake and anything else that is mostly on bank 2.

[Bdc101]

Originally Posted by 80stech

Looks like a vacuum leak affecting bank 2 so check the vacuum plugs at the back of the intake and anything else that is mostly on bank 2.

How would a vacuum leak affect bank 2 but not bank 1?

[Optllizer]

Originally Posted by Effduration

I agree that the lean condition only at idle is a little perplexing....

I have yet to see any 15-20yr old BMW ( I have 4 of them and have worked on a dozen others) not benefit from a proper smoke test, which includes smoking the brake booster.

Yeah, ill most likely do a smoke test soon. Any good recommendations? Something on the cheaper side. Do not need shop grade tester.

Originally Posted by 80stech

Looks like a vacuum leak affecting bank 2 so check the vacuum plugs at the back of the intake and anything else that is mostly on bank 2.

Ill take a look at these tomorrow morning.

Originally Posted by Bdc101

Since you switched O2 sensors and it didn't follow the sensor, and since bank 1 seems fine (both the trims and not throwing a code), it seems like the only thing left is the injectors - perhaps one of the injectors is throwing way too much fuel in?

One other thing to consider, is where does the secondary air get pumped into the exhaust manifold? I am not sure if there's one point for the whole manifold, or one point for each bank. I'm wondering if it was clogged on bank 2 then, could it throw that code. But if it's misfiring then this is probably not the case.


Also keep in mind that the P0174 is super common for all M54s of this age. It might not be related to your misfire. Just food for thought - not sure if any of this will help

If smoke test doesn't show anything, ill start looking at the injectors. What would be the best way to test an injector? just pull it out and see if it starts dripping fuel? Or just swap the 4-6 to 1-3 and vice versa.

SAP wise, the SAV thats connected to the engine is to the right of the Bank 1 O2 Sensor. Don't know if that would cause a lean condition. I did put seafoam in couple times to fix a old SAP error. Funny enough it didn't help since the issue was the Secondary MAF, it had power, but the sensor collapsed so it was reading that it was blocked.

Yeah I have looked at a lot of p0147 posts trying to find a solution. Some had the MAD going back, some were the ICV, some were just standard vaccum leaks. I hate how different it is for everyone.

I did think of a theory that I also will check out in the morning. What if while swapping the o2 sensor, I loosened a coil which is causing a vacuum leak or my misfires. Sounds really out there, but why else would I get a p0174 after swapping the o2 sensors. it would an interesting coincidence.

[Optllizer]

Also wanted to point out that the DISA Valve is in good shape and O-Ring is new. I had a old lean code for both banks cuz of the DISA O-ring and when I changed it both codes went away. This new lean code should be unrelated.