That doesn't follow. If you gut the DPF and introduce a 'calibrated' orifice into it to simulate the back pressure thenthe ECU will continue, fat, dumb and happy!

 

Julian.

 

But you can still see if the DPF is working (at least on the CR) by wiping your finger over the inside of the tail pipe.

VRS, 4x4 and Scout with the PD engine had DPF's

I apologise Scout and 4x4 too. That's still a lot of pd octavias without them though.

But you can still see if the DPF is working (at least on the CR) by wiping your finger over the inside of the tail pipe.

 

But you can wipe the tail pipe inside with a rag prior to an MOT - if you want to continue down these lines!

 

Julian

But you can wipe the tail pipe inside with a rag prior to an MOT - if you want to continue down these lines!

 

Julian

Give it a try and see how long it takes to soot up.

Give it a try and see how long it takes to soot up.

 

Plenty long enough conduct an MOT test. And how on earth will you be able to write an MOT requirement for a tester to wipe his finger inside the exhaust pipe to determine if a DPF is preesent or not. No exhaust is clean inside as a DPF is not 100% effective.

For the OP.

My car is a 07 vRS. SHARK Stage 1. DPF delete, and a straight through turbo back system ( no back box, no mid section )

I get both a fairly high pitched siren/whistling noise from the turbo as well as the perfectly NORMAL owl noise!

I love my owl noise and I too purposely induce it. For me I found if I boot it ( foot to the floor ) at low speeds in second gear and ease off/change gear at the same time between 2 and 2.5k I get a lovely whoosh/owl noise.

Car has been like that for 2 years ( since the gut ) including 40k miles and no problems. Enjoy your car, it's how the older style diesels work ( PD )

If they want to test for a DPF they'll just load the car up on rollers and watch for smoke.  Could possibly use a filter bag over the exhaust as a more objective test with a visible result (soot on filter vs clean filter).

 

I've run VCDS on my BMM (with fully functioning DPF) and found it runs quite rich.  I was calculating richer than 17:1 at full torque which will be emitting some soot.

 

An engine tuned to run without a DPF would be running closer to 19-20:1 at full torque and running further from the smoke limits.

Edited 4 July, 201510 yr by Kiwibacon