Hello all.
Some background on this.
Purchased the car in March of this year. Oil change, replaced plugs, air filter, cabin air filter, all 4 O2 sensor, replaced the fuel filter which has one of the regulators built into it. Eventually I replaced the PCV valve which was shot and oil was inside the intake manifold. Replaced the vacuum hoses on it and the intake manifold gasket. I used some of that Cataclean hoping that would clean something in the catties if that was causing something. Most of the engine hesitation is gone now, but still hesitates. After over 300 miles after the gasket, PCV valve, vacuum hoses were replaced and the Cataclean used, the codes came back today. I bought it off someone who had just replaced the MAF and intake boot. He wasn't a car guy in the mechanical sense and even called the mechanic when I was looking at it to verify what was done and even guaranteed the engine and tranny for 35 days after purchase in writing. One of the few honest people who Ive ever seen sell a used car. Car currently has about 208K on it. I even changed the tranny fluid and filter. I'm holding my breath that the catties are in need of replacing and taking them off to try and soak clean them will be a huge PIA. I'm wondering if anyone has any ideas. I've tried the carb cleaner before and after replacing the gaskets and valves and hoses but nothing is obviously showing or sounding. I did check the live data. A freeze frame did come up too about the P0430. The STFT on both banks seems like it might be off. Bank 1 STFT would be around 20% sometimes topping over 25%. It would stay around 12-15% most of the time. LTFT would be around 4-6%. Bank 2 STFT was about the same but stayed a bit higher, and the LTFT would be about the same as the STFT for Bank 2. Oddly, when I went to almost 3000 RPM Bank 2 STFT would bounce between 10-15% but the LTFT would drop to as low as -2.5, and Bank 1 STFT would go to 4.7-16.7% and LTFT would around 4.7% +/- 1%. I'm obviously missing something here. Part of me is thinking maybe the injectors need to be replaced, in part since I've read some people having similar issues and bad injectors solved their issue, and when I removed the injectors when replacing the PCV they were originals and coated in a semi solid oil.
Freeze Frame stated DTC causing the storage was P0430. Calculated LOAD Value was 45.9%. Coolant 201F. Bank 1 STFT 6.3%, LTFT 7.0%. Bank 2 STFT -1.6%, LTFT 10.2% at 2294 RPM, at 49 MPH, #1 Cylinder ignition Timing Advance 13.5, Absolute Throttle Position 39.6%, Air Flow Rate for MAF 504lb/min, Intake temp 93F, Commanded Secondary Air Status OFF
I have a feeling that it's something really obvious and simple I'm overlooking (like being stupid enough to buy a BMW, but it fell on my lap and I needed a car believe it or not), so any help will be greatly appreciated.
Thank you to everyone in advance and have a great weekend.
For my 2007 BMW X5, I had the latter two codes. P0420 P0430. 160,000 miles. It had a hard time accelerating past 60mph, and up hills.
Had the cats changed out. Solved the problem.
With yours, it may or may not be the case. Since it is accompanied with another code, which indicates the engine is running lean, P0171. I recommend looking into that problem first, and then maybe it will solve the problem downstream.
Once you rule that one out, then maybe double check that your O2 sensors are genuine BMW or (OEM like Bosch I think). BMW’s seem to finicky with the brands.
Curious to hear others thoughts. .
Hmm. Good point. It ran lean Bank 1 and Rich Bank 2 when I got it. I did cheap out on the O2 sesnors. I had to replace a new one on Bank 2 since it actually blew a day after installing it. I replaced it with the one working upstream I removed before and no problem with it since. It still runs lean bank 1, so using KISS method it could be the cheap O2 sensor since I bought two of the same and one already blew. It would be odd to have some kind of vacuum leak, even with aftermarket hoses, only affecting one bank. I guess I'll try peaking at and/or replacing it with a Borsh or at least better one and see if that has any effect. The hesitation is only mild right now, not like before. I was thinking of maybe rebuilding or replacing the DISA valve since at medium speeds and RPM it doesn't seem to hesitate and increases speeds without much problem but the cheap O2 sensor does seem like a rational place to start.
Thanks for the advice.
I'm curious to see what others have to say too. Hopefully I can avoid new cats for the time being.
Hopefully, either pressure cleaned or new injectors will bring it back into spec.
