Quick answer
Car Running Rich or Lean: the most common causes are failed oxygen sensor — ecu doesn't know actual exhaust oxygen content, dirty or faulty maf sensor — ecu uses wrong air quantity for fueling, fuel pressure regulator failure — inconsistent fuel pressure causing mixture variation. Metre Per Second (KPHB, Hyderabad) diagnoses the exact fault and repairs it same-day — typical work runs ₹3,000 – ₹9,000, with free pickup and drop across Hyderabad, OEM-grade parts and a 1-year warranty. Call +91 8555824915.
What causes Car Running Rich or Lean?
These are the faults we most often find behind this symptom on cars driven in Hyderabad's heat and stop-go traffic:
- Failed oxygen sensor — ECU doesn't know actual exhaust oxygen content
- Dirty or faulty MAF sensor — ECU uses wrong air quantity for fueling
- Fuel pressure regulator failure — inconsistent fuel pressure causing mixture variation
- Vacuum leak — unmetered air entering intake causing lean condition
- Stuck-open fuel injector — one cylinder always has excess fuel
Repairs & indicative pricing (INR)
| Repair | Indicative price |
|---|---|
| O2 sensor replacement | ₹3,000 – ₹9,000 |
| MAF sensor clean/replacement | ₹2,000 – ₹8,000 |
| Fuel pressure regulator test/replacement | ₹2,000 – ₹6,000 |
| Vacuum leak smoke test | ₹1,000 – ₹2,500 |
| Injector test & clean | ₹3,000 – ₹6,000 |
Final price depends on diagnosis. We share a written estimate before any work — no surprises. Free pickup & drop across Hyderabad, OEM-grade parts and a 1-year warranty.
Frequently asked questions
What are the signs of rich or lean running in Hyderabad?
Running RICH (excess fuel): black soot on exhaust, higher fuel consumption, smell of unburnt petrol from exhaust, black smoke, O2 sensor fault code. Running LEAN (insufficient fuel): engine hesitation under load, backfiring through intake, overheating, engine damage over time. Both conditions trigger OBD fault codes that Metre Per Second reads with a ₹500 scan to identify the root cause.
Related car problems we fix in Hyderabad
Why Hyderabad drivers choose Metre Per Second
- Factory-grade diagnostics — we read the real fault, not just a generic code.
- Free pickup & drop across all of Hyderabad — KPHB, Kukatpally, Miyapur, Hitech City, Gachibowli, Banjara Hills, Secunderabad and more.
- 1-year unconditional warranty on parts and labour.
- Transparent, written estimates — typically 30–50% below authorised dealers.