BMW & Mercedes-Benz
Exhaust & Emissions
O2 sensors, catalytic converters, EGR, flex pipes, and diesel emissions parts.
Compared to current list price at local franchise dealership parts departments. Same-day or next-day delivery based on order time and stock. Delivery radius measured from our Fullerton warehouse.
Common parts
- Oxygen sensors
- Catalytic converters
- Flex pipes
- EGR valves
- DPF (diesel)
- Clamps and gaskets
Counter diagnostics
Symptom → likely part
What we hear on the phone, and what it usually turns out to be. Read the data before you buy the part.
| What you’re seeing | Likely part | OEM or aftermarket |
|---|---|---|
| 01P0420 catalyst efficiency, no drivability issue | Post-cat O2 sensor first, then cat | OEM sensor |
| 02Rattle at idle that goes away at 2,000 rpm | Heat shield or broken cat substrate | Aftermarket shield |
| 03Exhaust smell at the firewall | Flex pipe cracked | OEM-supplier |
| 04Failed smog, readiness will not set | O2 sensor or an unfinished drive cycle | OEM sensor |
| 05Diesel in limp mode, regen incomplete | DPF loaded or a pressure sensor | OEM |
| 06Rough idle, EGR codes on a diesel | EGR valve or cooler | OEM |
| 07Ticking from the manifold when cold | Manifold gasket or a cracked stud | OEM gasket |
Fitment at a glance
BMW chassis
- N20 / N55 pre and post-cat
- B48 / B58
- F30 / F10
- X3 / X5
- 335d N57
Mercedes-Benz chassis & engines
- OM642 / OM651
- M274 / M276
- W205 / W212
- GLK / GLE diesel
Not a complete list. Send the VIN and we confirm the fitment before you buy.
What drives the price
Genuine, OEM supplier, aftermarket
California makes this category simple: catalytic converters have to be CARB-compliant, and that limits the field. Genuine converters are compliant by default and expensive by default.
Bosch, NGK, NTK and Denso build the oxygen sensors in both marque boxes. Buy the supplier-labeled sensor with the factory connector already on it and skip the splice.
Aftermarket is safe on clamps, gaskets, hangers and heat shields. On converters, only a CARB EO-numbered unit goes on a car that has to pass smog here. We will not quote anything else for a California car.
Three prices, one part
Dealer list
100%
The number on the franchise counter’s screen. Your baseline.
Our OEM price
−15%
Priced at least 15% under dealer list on the same genuine or OEM-supplier box, delivered.
Quality aftermarket
Lower
Named brands only, where aftermarket is the right call for this job.
Compared to current list price at local franchise dealership parts departments.
Same-day or next-day delivery based on order time and stock. Delivery radius measured from our Fullerton warehouse.
What usually sends these in
A catalyst code, a rattling heat shield, a failed smog, a diesel in limp mode.
BMW: Pre/post-cat O2 sensors across the range.
Mercedes-Benz: OM642/OM651 diesel emissions parts.
Serving
Free delivery on orders $200+ within 10 miles of Fullerton.
Questions
Exhaust & Emissions, answered
- Both. We quote genuine, OEM-supplier, and quality aftermarket side by side, then you pick the one that fits the job and the budget.