Hey guys! I've been struggling with my N14 for a while now. I'm hoping to get some answers or clues what this issue is.

So the car is actually a Peugeot 207 with a N14 engine. As I got it, i replaced almost everything:
- 4 new Bosch Injectors
- PCV blocked off
- New timing kit with VANOS solenoid
- Downpipe with a spacer for the downstream lambda
- New valve tappets
- Cleaned and machined head (all valves were machined(?) by a shop because they had a sharp edge.)

So the symptom is that the car under around 80% load starts "bogging", cutting out for a few seconds, and making pops like they are in the intake.
I did some live data viewing if something was off.

The most noticeable was when the car did that bogging, the Fuel Rail Pressure dropped down big time, but never had a misfire or any fuel pressure related code.
Also I checked what are the symptoms of a failing HPFP, but none of those symptoms were present in my case. (never had a cold start issue, the car never stalled)

Last code I had was a downstream lambda sensor - slow response. But that must be caused by the spacer on the lambda. So before I started putting money on a new lambda
I removed the spacer. No more slow response code, just the catalytic converter code which I don't care about.

Another thing I noticed, that the throttle position sensor's percentage is at around 15-16% on idle which I would consider okay because the car needs idle.

As for the ignition advance, it is very sus because while cruising it reads -30 ignition timing which i would consider advance, and then when I start pushing it, it only goes up to 0 degrees which isn't good.
Maybe the VANOS unit is the one playing a game?

Also the car is idling unevenly. You can't tell by looking at the RPM gauge, but you can feel it sometimes it drops a little then it corrects itself. The sparkplugs and coils were replaced last year.

I found a few videos on Youtube about rebuilding the HPFP, and read the forum topic about refreshing it. I have found a HPFP rebuild kit for about 200 with every seal, bearings, and the "pusher plate" for the pistons.
In January I will have a DS3 with the same engine at my house. I will try to swap the HPFPs and look what my car is doing with that, and then consider buying anything for it.


I am linking a few videos while driving. Look at the graphs.

 

I'll do my best to try to help you out. First things first, I would put the original catalytic converter back on and do another test. If you're getting CEL for the O2 sensors, it could be messing with your fuel and air intake as it is. The post cat sensor is trying to read the efficiency of the catalytic converter that I'm assuming is not there. So it's telling the car to run a certain way, all while your Pre-cat sensor is telling the car it needs more air or fuel. Another thing I can think of is that I know when I went catless, I ran the car for a week before getting tuned. And the CEL on from the O2 sensors would put me into limp mode and I wouldn't make any boost. So it could be taking some sort of effect to that and why it may be bogging or losing fuel on a pull.
My second thing would be your PCV block? Why did you block it off? I've read on here quite a few times that it shouldn't be blocked. I would try hooking that up again and see if anything changes. That's where I would start to try to pinpoint a more direct problem of what may be happening.

 

Hey! Thank you for your help.

I had used the car with the cat on, still had this issue.

As for the O2 sensor. When I had the spacer on, it never had a code since June of this year, just recently. Then I removed the spacer, as inticipated the CEL came on after a 15 kms but no limp mode, plenty of boost (you can hear the boost building up and blowing off).

For a few weeks now we've had wet roads in the area, it seems like when the wheel is spinning (barely no load on the engine), it revs fine.

Also I can rev the car over 3k, but only if I press the gas pedal until 1/3rd of its way. Thats how I've been using it for a while now.

Ohh and also.... have you seen the graphs? There is a 10ms injection time only on the 3rd cylinder. What could that mean?

BTW when idling, the Fuel Rail Pressure is hovering between 50-45 bars which I don't really know if it's fine. I know it's okay if it's 50.

I might just get 4 new plugs and coils to try. They aren't that expensive.

 

I think your HPFP is going out. I think 50 bar is too low. I believe it should be about 50 bar at idle. If you're revving and it is still at 50, then it sounds like that's bad. Also, you didn't mention your mileage on it, or if it's been replaced or not. But mine went out at about 70k or 75k miles on it. It would barely run. I didn't throw any codes or anything, but starting was a huge issue, especially cold. And I happened to get a used one and it's worked perfectly since. I don't know too much about rebuilding them, I know it was an issue and not recommended a few years ago when I was looking at them. But you could try.

 

I'm guessing that it is going out too. The mileage in the car is at around 80k in miles, and I don't know if it was replaced or not.
Haven't measured the depth of the diaphragm yet. That might be my next move until I get another HPFP to swap on to try it.

It's kinda funny how unpredictable this thing is. For the last 2 days I can barely push the accelerator pedal to 1/4rd until it starts popping and banging.
It seems it is very affected by humidity and temperature. The 2 map sensors have already been replaced...

 

Yeah the temp thing is weird. I said mine had trouble on cold starts. And it did. I had to keep it running by revving it. But once it got warm, it ran almost perfect. Could feel it still but I didn't have to keep it running at idle. Make sure to get a genuine one too. I tried going for one off of eBay, lasted about a week. It just went out too. Didn't even try to last. Had to put my original back on until the new one came.

 

I will be buying the PSA one. Not that HOFFER stuff which they selling around here in Europe.

The other thing might be my turbo. When the car was taken apart, I saw the wastegate arm wobbling around but it wasn't so bad like the ones they show on Youtube.
When I cruise on 3k for a few seconds then punch the throttle no bogging what so ever. At least with 1/3 throttle.
In 1st gear when I do the same, and rev it to like 4k there is no blow off noise, neither the feel of boost.
I know the turbo consumes some oil. I had already recognised it before when it's idling for 10 minutes it starts to smoke. But after I rev it a few times its gone.