Countryman Cold Start Engine Troubles

[Flavius_6IDA]

Hi all, I drive a 2016 BMW X1 with 159k+ miles, and I’ve been running into an issue that might sound familiar to Countryman owners:

• When it’s below 30°F, I often get these two codes:
  • Air Mass Plausibility: Air Mass Too High
  • Mixture Control: Mixture Too Lean

It usually happens after driving for a bit, though sometimes right after a cold start. The car hesitates briefly but drives fine otherwise. The codes clear themselves after a day or so. Here’s what I’ve tried so far:

• Fixed a loose intake connection after a smoke test.
• Replaced MAF, MAP, and T-MAP sensors last year.
• New coil packs, spark plugs, and air filter.

I’m wondering if it could be the high-pressure fuel pump or injectors. Has anyone experienced this or have advice?

 

[Fulke_Order]

Hi all, I drive a 2016 BMW X1 with 159k+ miles, and I’ve been running into an issue that might sound familiar to Countryman owners:

• When it’s below 30°F, I often get these two codes:
  • Air Mass Plausibility: Air Mass Too High
  • Mixture Control: Mixture Too Lean

It usually happens after driving for a bit, though sometimes right after a cold start. The car hesitates briefly but drives fine otherwise. The codes clear themselves after a day or so. Here’s what I’ve tried so far:

• Fixed a loose intake connection after a smoke test.
• Replaced MAF, MAP, and T-MAP sensors last year.
• New coil packs, spark plugs, and air filter.

I’m wondering if it could be the high-pressure fuel pump or injectors. Has anyone experienced this or have advice?

Those codes sound frustrating, especially with colder temps. Given everything you've replaced, the high-pressure fuel pump or injectors could be worth investigating. Have you had a fuel pressure test done? A failing high-pressure fuel pump might struggle in the cold, causing lean mixture codes. Another thing to check is the PCV system, cold weather can cause condensation or blockages that mess with air-fuel ratios.