325I 05 codes p0171 p0174

[Trak]

I’ve been getting these codes for roughly 1 yr n a half today as I was driving every time I apply gas my car would began to die then eventually it died completely and I had to roll to the side of the road I checked the codes in these codes (p0171 & p0174) pop up at the same time. I had previously told my mechanic that I may have a leak somewhere and he blamed it on weather.

Could anyone one point me to the possible issue to this problem?

i was Interstae 16 going a good 80 95mph when the issue started. I know they are system lean codes

[All2kool]

These two DTC's are the most common codes your BMW will throw and can be caused for a variety of reasons, the most common being a vacuum leak. Your first course of action is to visually inspect the Intake Boots for cracks. The second step is to have a Smoke Test done to determine a vacuum leak. There are other causes for these two codes including a DISA that fails a vacuum check. You can Google 'DISA vacuum check' to see YouTube videos. Good luck.

[MarcoZandrini]

The intake needs to undergo a smoke test. Try to www.bimrs.org to find a shop that specializes in bimmers in your area.

[All2kool]

A loose sealing Oil Cap can cause a vacuum leak. The O-Rings on the dipstick being old can cause a vacuum leak. There are lots of things you can check on your own before paying someone to do a smoke test, which can also find a vacuum leak.

[yukon101]

If it was instantaneous I am thinking fuel pump causing fuel starvation. Vacuum leaks for me in my 740i were only apparent at idle and sometimes while driving.

[Jackson42]

Symptoms point to the fuel pump. too much air and not enough fuel can give the same symptoms. What is the mileage on the car?

[All2kool]

Symptoms point to the fuel pump. too much air and not enough fuel can give the same symptoms. What is the mileage on the car?

Yes, the Fuel Pump can also cause a lean code. The OP should test the Fuel Pressure to determine that. On the bright side, the Fuel Pump is a 30 minute DIY to replace and not that expensive. I replaced mine as a preventative measure.

[MarcoZandrini]

The only fuel pump to buy is one made by Siemens/VDO. The fuel filter should be replaced at the same time. The fuel pressure regulator is built in the filter. Check the fuel pressure at the test valve on the fuel rail under the black plastic engine cover. Pressure has to be at least 50psi at all engine speeds.

But have the intake manifold smoke tested first.

[Trak]

My miles are like 157k I just had my mechanic look at it seeing that I don’t even have the time between work and my kids. The initial breakdown was like it was struggling to accelerate as I applied the gas then I came to a complete stop and applied gas and it accelerated a little more but as soon as I attempt to apply more gas say 40 mphs it just started to decelerate. And the only codes to pop up are the system is to lean. I’m praying it’s a easy fix. I use only original parts so theirs no after market or anything other than original parts.

[All2kool]

My miles are like 157k...

A Fuel Pump is only good for so long with no real average mileage. Some last 200k miles, some less than 100k. It's easy to check if yours is original to the car. Remove the bottom of the back seat. Remove the 4 hex nuts (10mm I think) on the cover, passenger side. Look at the clamp on the rubber hose. If it's one of those 'pressed on single use type', your Fuel Pump is original to the car. Also, the top of the Fuel Pump will appear discolored and grimy after 157k miles.

[Trak]

My mechanic got back with me he said I will have to change the fuel pump and the fuel transistor or injector I don’t know which one it’s called and all the parts that come along with it he said it seems like the car is not getting as much fuel as it needs to run, he also said they have updated some of the parts that comes along with the fuel pump and fuel transistor or relay or whatever he was trying to tell me so I might as will just replace everything has to do with it he’s charging me 1160.58. The thing is I looked up most of the parts and I can probably purchase those parts under what he’s charging me. But his is the only mechanic in town that specializes with BMWs so I might not have a choice unless that price range seems a little bit right for time and parts and labor

[All2kool]

My mechanic got back with me he said I will have to change the fuel pump and the fuel transistor or injector I don’t know which one it’s called and all the parts that come along with it he said it seems like the car is not getting as much fuel as it needs to run, he also said they have updated some of the parts that comes along with the fuel pump and fuel transistor or relay or whatever he was trying to tell me so I might as will just replace everything has to do with it he’s charging me 1160.58. The thing is I looked up most of the parts and I can probably purchase those parts under what he’s charging me. But his is the only mechanic in town that specializes with BMWs so I might not have a choice unless that price range seems a little bit right for time and parts and labor

Two things:

1. Find another mechanic.
2. The Fuel Pump is less than $121 and is an easy DIY. Give yourself 45 minutes to replace it the first time and if you ever need to do it again, it'll take 15 minutes.

[Trak]

Later this week I’ll upload the repairs he made, the problem was solved.