Ford Focus RS Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
2,369 Posts
Discussion Starter #1
Some background: Since early this year, I've been getting an intermittent P0171 "Bank 1 Lean" code, but with no discernible drivability issues: idle seems ok, no hesitation, etc. I would simply clear the code and keep driving until it would pop back up after a month or so, rinse and repeat.

It has recently popped up again, so I decided I've had it and will try to address it, so I started doing my research around here and have found a handful of related threads, but not the same symptoms.

As part of my investigation, I started looking at my AFR, Fuel rail pressure, STFT and LTFT in various conditions: varying RPMs, loads, etc. One thing that looked funny was that at idle, my AFR (14.5-14.9), FRP and STFT (-2% - 3%) would look relatively normal but my LTFT would be stuck at 26-29%. An old datalog I took about a year ago showed a LTFT of around 7-8% at idle, so this to me suggests that I've developed some kind of vacuum leak.

I started looking around my engine back hoping to find something loose or left unplugged, but did not finding anything. What I did find was a good amount of oily residue all around my catch can.

344844

Now, I'm not sure where it could be coming from, but I'm suspecting it's at the quick disconnect or maybe a bad o-ring on the can itself.

My question is: Anyone with a UPR catch can have oily residue issues around the can? Could this cause a vacuum leak that can trigger a P0171? Does anybody know what the fittings are called and what size they are? Does anybody know how to replace these types of fittings? I really don't want to have to dig down and reroute a new line.

Any input would be much appreciated!
 

·
Registered
Joined
·
1,649 Posts
You can try the butane/propane test to see if there is a vacuum leak.

Have you considered changing the HP fuel pressure sensor?
 

·
Registered
Joined
·
829 Posts
Some background: Since early this year, I've been getting an intermittent P0171 "Bank 1 Lean" code, but with no discernible drivability issues: idle seems ok, no hesitation, etc. I would simply clear the code and keep driving until it would pop back up after a month or so, rinse and repeat.

It has recently popped up again, so I decided I've had it and will try to address it, so I started doing my research around here and have found a handful of related threads, but not the same symptoms.

As part of my investigation, I started looking at my AFR, Fuel rail pressure, STFT and LTFT in various conditions: varying RPMs, loads, etc. One thing that looked funny was that at idle, my AFR (14.5-14.9), FRP and STFT (-2% - 3%) would look relatively normal but my LTFT would be stuck at 26-29%. An old datalog I took about a year ago showed a LTFT of around 7-8% at idle, so this to me suggests that I've developed some kind of vacuum leak.

I started looking around my engine back hoping to find something loose or left unplugged, but did not finding anything. What I did find was a good amount of oily residue all around my catch can.

View attachment 344844
Now, I'm not sure where it could be coming from, but I'm suspecting it's at the quick disconnect or maybe a bad o-ring on the can itself.

My question is: Anyone with a UPR catch can have oily residue issues around the can? Could this cause a vacuum leak that can trigger a P0171? Does anybody know what the fittings are called and what size they are? Does anybody know how to replace these types of fittings? I really don't want to have to dig down and reroute a new line.

Any input would be much appreciated!

I had some fun doing this exact thing on my 2016RS. Here ya go, easy check, hardest part is making the kit.
 

·
Registered
Joined
·
2,369 Posts
Discussion Starter #4
You can try the butane/propane test to see if there is a vacuum leak.

Have you considered changing the HP fuel pressure sensor?
No, have not tried the carb cleaner test yet, but plan to over the weekend.

I have the fuel rail pressure sensor and thje EVAP solenoid assembly on order to narrow things down, just trying other things in the mean time.
 

·
Registered
Joined
·
2,369 Posts
Discussion Starter #5

I had some fun doing this exact thing on my 2016RS. Here ya go, easy check, hardest part is making the kit.
Just send me your smoke tester, I'll pay for shipping! lol
 

·
Registered
Joined
·
5 Posts
I had the UPR CC. After install I ended up with so much oil vapor smell in my cabin due the leak and it being next to the passenger fresh air intake. I could see the residue where oil was escaping where the hoses screw into the can. I tried to use teflon tape, tightenining the fitting, finagling with the quick disconnects as well, but my car still reeked of oil.
Ended up sending my CC back.
 

·
Registered
Joined
·
2,369 Posts
Discussion Starter #7
I had the UPR CC. After install I ended up with so much oil vapor smell in my cabin due the leak and it being next to the passenger fresh air intake. I could see the residue where oil was escaping where the hoses screw into the can. I tried to use teflon tape, tightenining the fitting, finagling with the quick disconnects as well, but my car still reeked of oil.
Ended up sending my CC back.
I actually just noticed this recently. Catch can was clean after my last oil change 6 months ago, so it was a recent development. I haven't noticed any oily smell in the cabin, although I did just replace the cabin air filter recently as well with a better HEPA+activated carbon filter due to all the recent fires in my area. I just got in contact with UPR and they have been very helpful so far feeding me with things to check.
 

·
Registered
Joined
·
2,369 Posts
Discussion Starter #8
Quick update:
So I got some support from UPR and they have advised me on cleaning and resealing the catch can. Did that over the weekend and my high LTFT at idle still persists, so that was not the culprit.

Did the propane test (basically like this below), and did not find anything.

For kicks, I decided to flash an older tune from a different tuner to see if that changes anything. As far as I can tell, nothing has changed, so it's not tune related.

Did some more data logging to look at different conditions. For those who are curious, here are a few logs I've taken:

Warm idle:

1.5k rpm stationary:

2.5k rpm stationary:

2.5k rpm freeway:

Different tune/tuner idle, 1.5k and 2.5k rpm stationary w/ evap channels:
 

·
Registered
Joined
·
5 Posts
Have you checked all the connections under the intake manifold as well? When I installed my CC I found the plastic connector housing under the intake manifold (i believe its normally round) was 1/4 broken on mine. I can only guess this happened when the head gasket was replaced. I would even go so far as disconnect and fully re-seat any related vacuum lines just in case something isn't seated or has a broken catch. A loose connector could explain the intermittent issue.

Edit: How does the O2 sensor look and its connection.
 

·
Registered
Joined
·
2,369 Posts
Discussion Starter #10
Have you checked all the connections under the intake manifold as well? When I installed my CC I found the plastic connector housing under the intake manifold (i believe its normally round) was 1/4 broken on mine. I can only guess this happened when the head gasket was replaced. I would even go so far as disconnect and fully re-seat any related vacuum lines just in case something isn't seated or has a broken catch. A loose connector could explain the intermittent issue.

Edit: How does the O2 sensor look and its connection.
I have not visually checked the connections under the intake manifold, but I did stick my propane hose down there. Will have to further investigate that area. I agree that unplugging and reseating all the vacuum lines is a good idea. Thank you.

I have not looked at the O2 sensor at all since it's super buried behind the engine. Will check that out this weekend.

Is there any way to check O2 sensor condition by data logging? AFRs seem ok but does fluctuate a lot, but figured that was normal.
 

·
Registered
Joined
·
1,649 Posts
Maybe a silly question, but do you have any pending codes?
 

·
Registered
Joined
·
5 Posts
Can check with an Obd2 reader. I can't remember if/where it's at on the access port functions. I managed to get my car CPO warrantied so no longer run a tune or the AP.


Oxygen sensor - Wikipedia

The wiki is just a good read too for how it works for troubleshooting purposes.
 
1 - 13 of 13 Posts
Top