Fuel trim Issue???
 

When you have the Idle Load Fuel Trim bank1 and 2, limit reached, doesn't it mean that u can unplug the Air flow sensor to check? To correct this problem you need a new MAF, (2) pre cat O2's and possibly seal up the intake? Any suggestions?
Thanks

errors:
#27 IDLE LOAD FUEL TRIM 1 LIMIT REACHED
#35 IDLE LOAD FUEL TRIM 2 LIMIT REACHED


97 540i 164k miles.

Since your getting both banks to have faults in them its eather your MAF like you said, possible PCV intake leak, your intake boot is off the throttel body causing unmetered air leak, or you have a air leak somewhere past the MAF.
MAF's do tend to go on v8's, but so do PCV valves.

With the engine running spray down the back of the intake with brake clean. If the idle increase then you have a PCV leak. If it doesnt incease, spray down the front intake boot and around your MAF.
If that still doesnt do anything you might want to get the codes read out by a dealer and get a defenate on what the problem is.

Antiburn is correct, PCV is most likely cause. There could be an air leak at the front seals on the intake as well, for the throttle body. Usually, if we do a PCV (or backing plate), the intake comes off and all it's seals are replaced as well.

It's very unlikely to need both oxygen sensors at the same time. The sensors are simply giving the feedback of a lean mixture, the problem is elsewhere.

I also got error #115 HOT-FILM MASS AIR SENSOR
 

thanks guys for ur suggestions, I really appreciated.
I'll try that tomorrow when I get the Brake Cleaner.

Where is the PCV located and where should I apply the Brake Cleaner exactly? :confused
Could you please tell me which part# on the diagrams I've attached below


I also got error #115

HOT-FILM MASS AIR SENSOR

I've cleaned the MAF Sensor with "CRC Mass Air Flow Sensor Cleaner" and derived the car 55 miles now, CEL did not popped up yet.

I'm not sure that the error #115 came before i cleaned the MAF or after.

I just cleaned the ICV as well, it was really dirty inside.

many thanks

Maybe you can replace the realoem.com hotlink images with static screen shots

The PCV is squarish in shape, and bolts to the rear of the intake manifold. Follow the large vacuum line from the brake booster and it'll go right to it. If no leak is found there, spray all around the intake to check all the gaskets.

Picture#1 Part#2 (COVER #11617501563)?
 

Since you got a fault for HFM your problem is most likely that.

The PCV is picture #2, you will need
Quanity
1 - 10
1 - 2
1 - 17
10 - 13
4 - 14
1 - 11
And 2 cans of brake clean to clean out the inside of the intake and surrounding parts.
If your doing the PCV yourself take pictures before you dissassemble, the throttel cables are tricky to put back together.

I've found the intake leak :)
 

Thanks a lot guys, I really appreciated your help.
I believe I've found the intake leak. It's on the front intake boot, between the front Intake Manifold and the FLANGE where the Throttle Housing mounted is.

I've used carb cleaner, as I sprayed around the front intake boot the rpm changed extremely. I couldn't notice a leak somewhere else.

What else should I replace at the same time when I do the front profile gasket and which parts I do need except part#11?

:thanks

Only 11 if your doing the seal between throttel body and intake.
Make sure the larger rubber o-ring is there when you take the intake boot off the throttel body.
Part # 7 13541747475
http://www.realoem.com/bmw/diagrams/z/a/221.png

Loosening Tight Screws?
 

I was just planning to buy tools and do this myself but then I changed my mind and went to an independent mechanic. This was a bad decision :shoot He even couldn't take out the bolts/screws from the Throttle Housing and then tried to remove one of the flange bolts/screws from the intake boot. I then said "it's OK buddy" and leave the shop.
Now I'm planing to do this myself, any suggestions or DIY's how to take out the bolts/screws without strip off any of them?

Thx

Code P0420 after fixing P1174 & P1175 issue.
 

Both codes (P1174 & P1175) has gone away after I've replaced the front intake boot profile gasket. But after 180 miles I've got the code P0420 "Catalyst Efficiency Below Threshold (Bank 1)" :cry I never had this code before.

What I've done:
-Replaced CCV (11/06, approx. 15k miles ago)
-Replaced Camshaft position sensor (11/06, approx. 15k miles ago)
-Replaced Crankshaft position sensor (11/06, approx. 15k miles ago)
-The Cats were replaced at least 25k miles ago. I don't know if they are OEM or aftermarket. They look to me like aftermarket. The previous owner had them put on.
-Cleaned MAF (2-3 weeks ago)
-Cleaned ICV (2-3 weeks ago)
-Replaced both pre-cat O2s (2 weeks ago)
-Replaced the front Intake boot profile gasket (last Friday)


I even passed the AZ emission test after cleaning the MAF & ICV with the old O2 sensors.

post-cat sensors, leaking exhaust system or in worst case a new Magnaflow 43005 for Bank 1?

Any thoughts are appreciated.

Ive replaced 2 brand new aftermarket cats on an e38 due to insufficent cleaning. It did throw a fault because they were not to OEM specs. With the fault code you go its looking like your cat is not cleaning like it should, or I should say its not cleaning to BMW specs.