Xr50T Cat Restriction Ring

[Barra]

Currently in Euro 4 exhausts, not sure if in the F6, is a restriction ring, from what I understand it's there to aid the cat in heating up quicker than previous models as the cat is very close to the turbo, yet at operating temp it's effectively a 2.5" system from the start. I've gone ahead and had this ring removed today with a die grinder as it's only held in with 3 small welds. This is located on the outlet from the cat section of pipe at the flange.

I was concerned that it may throw up a warning light, yet after 160 Kms of driving no dramas there, it definately flows much better, no change in sound though.

Does come on boost noticeably earlier now too.

I did notice on my dashhawk that the cat temps actually drop when idling and usually sit aroung 850 Degrees when at operating temp, now sit on 700.

One more thing, the bolts used to connect the flanges, are slightly rectangular and can strip easily.

'10 FG XR50T

[_John_]

[ratter]

I would think that the cat temp readings is coincidental, these figures are predictive not factual so unless software changes were made it would still think things were normal, but good to hear it goes better.

[Barra]

Agreed. Yet never seen the temp drop at idle.? Could the faster flow through from the turbo be cooling it somewhat, with that slight back pressure gone now? My Dashhawk gets readings from the OBD2 Port. Noticed Mv on 2nd O2 sensor is different, yet no engine light. Curious if an aftermarket cat was put in place would it read differently or give warning, without a tune. Does the new F6 Euro 4 have the same restriction ring?

[ratter]

What I was saying is, even if the cat temp was lower the ecu would not know this as there is no sensor to check it, it is a predictive number based on what the ecu thinks is happening based on the programming equation that is in the ecu

The o2 readings should be different, this is how the ecu knows the cat is functioning as it is designed to do, a different cat will start to get the rear o2 working similar to front and will trigger the MIL light whan the computer does a diagnostic trip od the cat

[Barra]

So where do I get the reading in Degrees for cat temp from, that I have on the dashhawk? Must be a sensor for it, or does it calculate this reading from other imputs?

I'll stop questioning it and enjoy.

Hope the info helps others looking to do minor mods with std exhaust. Plus spoke to a lead mechanic at a ford dealership, and he wasn't even aware it existed. Not saying much though.

[ratter]

the reading is what the ford ecu has predicted, the dash hawk is just reading this, there is no sensor, the ecu wants to know rough cat temp to turn on cat protection when needed etc

[Barra]

Thanks for the info.

[ratter]

welcome

[MexicanBatman]

cat protection?

whats the change when this occurs?

less timing/boost? more fuel?

hmmm...