S52 OBD II Stumbling issue

[DesertBMW]

Update: we found a problem it was bad Tecnica motorsports flash tune

[The Volta]

Changing the o2 sensors today if the end up coming in the mail, they were reading a constant .980 volts and were not changing at all.

[The Volta]

Fixed the headlight issue, it was a ground that came off and fixed those issues.

Tried to relocate a ground that i had to the oil pan and still no fix.

Still having the same issues.

[DesertBMW]

P0135:Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
P0141:O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)

Check 02 sensor relay, it is one of those 3 that sit near harness connectors.

Always work with first codes

[The Volta]

Changed out the fuel filter/cleaned out the MAF and switched the O2 sensors. Still nothing changed at all.


The hunt continues.

[DesertBMW]

work with the codes first on the list

[The Volta]

P1250
P0135:Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
P0141:O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)
P0306:Cylinder #6 Misfire
P0446:Evaporative Emission Control System Vent Control Circuit Malfunction
P1189:Fuel Control (Bank 2 Sensor 1)
P1188:Fuel Control (Bank 1 Sensor 1)
P0173:Fuel Trim Malfunction (Bank 2)
P0170:Fuel Trim Malfunction (Bank 1)

Soooo.... Looks like i have some stuff to work out. I am going to start at the fuel filter leak issue to see if that might be part of the issue, then check for some vac leaks.



TPS sensor was working correctly, im going to have to post the other numbers as i couldn't start the car due to it being to late out.

I am also going to do a pressure test on the rail to see if that could show up any short comings.

Thanks for the input, i will do what you said about the 02 sensors too and see if they go away.

[jrdeamicis]

If you mix the 02 sensor plugs on top of that manifold it will do that and trow "fuel trim bank1" code.

Pull codes asap.

Use some live data to check some things out. I would immediately check fuel pressure and other basic engine requirements


LTFT (Long term fuel trim) Post the percent amount.
TPS - Ensure the throttle is 0-100%
RPM - An inconsistent RPM signal or inaccurate is a sign of crank sensor / cam sync problems.
O2 Diagnosis (Or swapped sensors - as Desert mentioned)

[DesertBMW]

Nope, its the OBDI manifold with the OBDII Fuel rail and remote FPR.

If you mix the 02 sensor plugs on top of that manifold it will do that and trow "fuel trim bank1" code.

[The Volta]

Nice to see you in AZ. So you did OBD2 with OBD1 intake manifold, fuel rail fuel regulator?

Nope, its the OBDI manifold with the OBDII Fuel rail and remote FPR.

[DesertBMW]

Nice to see you in AZ. So you did OBD2 with OBD1 intake manifold, fuel rail fuel regulator?

[The Volta]

So, I am having issues, thus this shit post.

Symptoms:
1. No power above ~3k and stumbles pretty bad.
2. Shit throttle response.
4. HID lights are flickering on and off (unrelated?).
5. Sprung a leak before the fuel filter (maybe its clogged).
6. Misfires and Backfires a dickload.
7. fuck.

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Steps Taken:
I am going to pull some codes on the car tomorrow to see whats up, fix some of the obvious issues like the fuel filter and go from there.

Also going to try my friends S52 MAF too.



Watch this, it wont make you as mad as I am.