modifications > UPR Catch Can & Mountune Breather Plate

Why did you put a UPR Catch Can & Mountune Breather Plate on your RS?

The Focus RS has a direct injection gasoline engine. With each injector inside the combustion chamber instead of spraying upstream of each intake valve this leads to problems. In a non-direct injection gasoline engine the injectors somewhat clean the intake valves when the fuel is sprayed in the intake manifold before making its way into the combustion chamber. In a direct injection engine (and some non-DI engines) the intake valves, intake manifold, intercooler and piping can get coated with a light film of oil from the high crankcase pressure.

The UPR Catch Can and Mountune Breather Plate are a 1-2 combination against oil consumption and contamination in the intake tract. The Mountune Breather Plate replaces the factory breather plate that mounts to the engine block below the intake runners. The Mountune Breather Plate has a few diverter plates that make a tortuous path that makes it difficult for oil to follow. The crankcase pressure can vent, but the oil mostly stays put. If any oil makes its way to the UPR Catch Can it settles out in the bottom. Periodically the UPR Catch Can will be drained (every oil change is a good frequency). Depending on how much blow-by exists in your engine you may find anywhere from nothing up to a few teaspoons of oil between oil changes. It really depends on how you broke-in your engine. Once the crankcase air passes through the UPR Catch Can it gets sent to the intake manifold to be burned in the engine (minus the oil of course).

Date Completed:



- UPR Catch Can Kit, Upgraded check valve, Oil cap breather (all from Tune+)
- Mountune Breather Plate (from Mountune USA)
- Something sharp to trim factory breather plate gasket to fit Mountune Breather Plate (I used a pair of dike pliers)
- Masking tape & shop rag to temporarily block off cylinder head intake runners & intercooler piping from debris during disassembly/reassembly


- 1/4" & 3/8" drive ratchets, handful of extensions, wobblers, various sockets (8mm, 10mm, 11mm, 18mm)
- Flatblade screwdriver to remove factory breather plate fitting
- Lighter to remove factory fittings from breather hose
- Allen wrench to remove/reattach Mountune Breather Plate support bracket for factory breather connector
- 3/8" Torque wrench (15 lb-ft, 35 lb-ft)
*A friend for moral support is always optional. If friend isn't available Pandora will suffice.

Catch Can History:

- 12/02/17 = 90 mL at 3,000 miles
- 09/22/18 = 50 mL at 4,127 miles
- 04/26/19 = 40 mL at 4,953 miles after HG Recall fix
- 12/08/19 = 40 mL at 5,579 miles = 92 autox runs since HG fix
- 11/27/20 = 14 mL at 6,110 miles
- 05/29/21 = 30 mL at 6,480 miles


1. Install takes about 1.5 hours or so. I took my time because of taking pictures for this website.
2. No undertray removal. That's a win in my book any day.
3. I recommend doing this swap on a somewhat cold engine. Otherwise you will get roasted a few times in cramp quarters near hot engine spots.
4. Lay things out as you go (old vs new). UPR instructions are meh. If it doesn't fit don't force it. Try not to zap yourself near the alternator/starter. Only wusses disconnect the battery.
5. Only (4) wiring plugs need to be disconnected for this swap. MAP sensor, Gray Connector #1 + Gray Connector #2 (both behind intake manifold), and the Throttle Body Connector.
6. Use lighter to remove both fittings from factory hose between breather plate & intake manifold. Re-use fittings on both the Mountune Breather Plate and UPR Catch Can hose.
7. Follow the annotated pictures. Don't connect the UPR Catch Can hoses backwards because it won't work right. :)
8. Re-use the factory breather plate gasket on the new Mountune breather plate. Trim the one teat shown in the photograph so it fits. Teat, look it up. ;)
9. Torque specs = 15 lb-ft for (5) intake manifold bolts, 35 lb-ft for 18mm passenger side engine mount bolt.
10. Leftover parts = factory breather plate and hose (minus both fittings), factory oil cap.
11. Looks stock!
12. Easily reversible back to stock.