P code expert?? What's the trim "system"?

[upallnight]

Can you monitor the voltages on the 02 sensors on Bank 2. The combined value for the ST and LT for bank 2 is close to 14%. The LT appears to be right, but the ST is adding fuel to the mixture. With a LT in the positive the ST should be in the negative and not in the positive as the freeze frame data indicated. Did you replace any of the 02 sensors?

Which app are you using on your phone?

[upallnight]

Here's a video I made for another X forum poster on 02 sensors. The video shows the precat and post cat sensors voltage as the engine is in close loop.

The precat sensors are on the left, the post cat sensors are on the right. Bank 1 is at the bottom of the screen and bank 2 is at the top of the screen.

Post cat sensors voltage should almost be constant without a large fluctuation in voltage. If your post cat sensors have a large fluctuation then you need to replace the catalytic converter(s).

https://www.youtube.com/watch?v=zyh_4SktmFM

[kevinkay]

Originally Posted by upallnight

Can you monitor the voltages on the 02 sensors on Bank 2. The combined value for the ST and LT for bank 2 is close to 14%. The LT appears to be right, but the ST is adding fuel to the mixture. With a LT in the positive the ST should be in the negative and not in the positive as the freeze frame data indicated. Did you replace any of the 02 sensors?

Which app are you using on your phone?

ALL my O2 sensors are new, I am using OBD Fusion app
thanks

[upallnight]

When you replaced the 02 sensors did you unclip the harness one at a time and install a new sensor, or did you unclip all the sensors wiring harness and went back to reclip them all once the new sensors were installed.

Wouldn't be the first time that a DIYer might have connected the sensors incorrectly.

[kevinkay]

One at a time, was carful not to mix them up.
Is there an easy way to check/make sure?

[bcredliner]

In post 3 you mentioned you changed the O2 sensors and it was shortly after that the code appeared. I suggest checking the connections to the sensors, especially the pre cat sensors, if all OK swap them out and see if code moves. As mentioned, I don't trust cheap sensors either. Since air/fuel mix is so critical I would go to OE or OEM sensors at some point.

I know you have done a smoke test twice. However, some vacuum leaks take an extended period of time to show up even with a constant 2-3 psi and tons of smoke for several minutes. Also, the vacuum leak could be internal which would not show up in a smoke test. Is the rough idle there when engine is cold and also when hot?

Have you done a leak down test?

Have you done the test in the video Upallnight posted where pressure gauge is connected to the fuel rail to test constant fuel pressure and especially the one where the engine is run and then shut off to see how fast the fuel pressure drops off?

[kevinkay]

Thanks.
The new O2 sensors were Bosh and the retailer was gracious enough to let me exchange the pre and post sensors in bank 2 under warentee to rule out defective sensors (which they said is VERY uncommon). I then even swaped the pre's once again and have reseated all of them several times.

My idle issue is only felt after warm up. I woke up in the middle of the night last night and realized I did not re-check the O ring on the oil dipstick that was replaced/reseated when I did the CCV kit last weekend. Could be a small vac leak there causing new idle issue??

I did not do a leak down test, I think that means a compression test where you leave the valve connect to see if it leaks down? I have no new oil consumption issues if that's any sign of valve problems.

My fuel rail pressure is consistent at idle with the car running, after shut down and the pump off it drops to zero in about 30-60 seconds.

When I say "smoke test" I am using a harbor freight hand pump, cigar and I blow into the tube for pressure. I have held pressure for about 3 min with my finger on the tube. Then either lifting my finger or lifting the oil fill cap - I get the "puff" of pressure release. I do notice the interior gets a linger of cigar smoke even with the windows and doors all closed.

[bcredliner]

A vacuum leak at dipstick seal would be there all the time nor would it cause a problem on only one back.

Yes, leak down test is opposite of compression test. Poor results are not limited to valves. Since you have done so many things, while it is long shot but---

Pressure dropping that fast is not normal. Should take 15-20 minutes to drop significantly and still would be a long way from zero. I would focus on fixing that as it may well be related to rough idle issue.

IMO smoke test you did would not be conclusive.

[bcredliner]

Pressure should take 15-20 minutes to drop significantly. Go to about 3 minutes into this video I posted earlier. https://www.youtube.com/watch?v=V8xy3SNfnTQ

[bcredliner]

Vacuum leak at dipstick would be all the time and affect both banks.

Yes, leak down test is opposite of compression test but does check more that just leaking valves. It is a long shot but---

IMO smoke test was not conclusive.

That said, your focus should be on correcting the fuel pressure bleed down. Rough idle could be symptom of fuel pressure issue.